MUSHROOMS: WHAT THEY ARE AND WHAT THEY DO
PROFESSOR JOHN AROYE OKHUOYA
B.Sc (Benin) 1974 Ph.D (Wales) 1981 M.I. Biol (LOND) C. Biol (LOND)
PROFESSOR OF MYCOLOGY AND MUSHROOM BIOLOGY
INAUGURAL LECTURE SERIES 114
UNIVERSITY OF BENIN,
MARCH 3rd, 2011.
1
DEDICATION
This Lecture is dedicated to my biological father, Mr. Aroye Okhuoya (1926-2009)
who gave me all I needed morally and materially to attain the highest academic
qualification. And also to my spiritual father, Archbishop Benson Idahosa, of
blessed memory (1938 – 1998) who nurtured me spiritually, trusted and believed in
me and entrusted with so many responsibilities including planning and establishing
Benson Idahosa University. He imbibed in me the discipline of hard work and selfesteem.
2
PREAMBLE
HOW MY JOURNEY INTO THE WORLD OF MYCOLOGY BEGAN
First and foremost, I wish to give all glory, honour and adoration to Almighty God
for His grace to stand here today, to give the 114 th inaugural lecture of this
University, my Alma matter.
I gained admission into this University in 1970 and started a journey (man was so
limited to know about), but God Almighty, for He alone knows the end from the
beginning.
3
I enrolled to read medicine, but could not meet the requirement to be among the
first twenty that Ahmadu Bello University (ABU) could accommodate in helping
the young Midwest Institute (MIT) then. So I had to settle for B.Sc microbiology.
This course introduced me into the microbial world during which I met Prof.
D.K.G Ayanru, who led me into a kingdom – The kingdom of fungi. While my
colleagues were frightened with the many mycological names, I found myself very
comfortable with the terms. Before long, I started admiring the “American
pronunciation” of these terms by my American trained supervisor who I now
regard as my academic father. Please, give Prof. Ayanru a round of applause.
Just before my graduation, Prof. Ayanru believed in me and challenged me to write
up my long vacation project titled “Macrofungi in dungs of herbivores” which I
presented in the 4th National Conference of Nigerian Society of Plant Protection in
IITA, 1974. This presentation fired me on into the Science of fungi.
Finally, it was my PhD supervisor Dr. Ray Harvey of blessed memory who
eventually led me to the final destination of “mushroomology” in Cardiff (Wales).
INTRODUCTION
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Mushrooms are a special group of fungi which are saprophytic in their life
patterns. They lack chlorophyll and consequently cannot use solar energy in
manufacturing their food. They have been part of fungal diversity for centuries.
Their mode of nutrition is by producing a wide range of enzymes that can break
down complex substances after which they are able to absorb the soluble
substances so formed. This is characteristic of mushrooms (Chang and Miles
1992). They play a major role with other fungi and bacteria to rid our environment
of the litter, logs and wastes that would have clogged our cities and woods. They
do this by degrading them hence they are often referred to as decomposers in the
ecosystem.
These mushrooms breakdown the complex substances progressively into simple
inorganic elements which are then freely available to be reutilized. So, mushrooms
and indeed fungi are our friends.
In prehistoric times, man certainly must have used mushrooms as food and also as
medicines. The Greeks, Egyptians, Romans, Chinese and Mexicans and even
Africans had good knowledge of mushrooms. They regarded some species as
delicacies and others they used for religious purposes and tradomedical practices.
These were collected from the wild for the various uses.
Many have died by eating mushrooms (certainly poisonous species). Poisonous
mushrooms have claimed the lives of historical figures in history. Such casualties
include Pope Clement VII, King Charles VI of France and Czar Alexis of Russia.
The most celebrated casualty was that of Roman Emperor Claudius Ceasar. There
was however the belief that the mushrooms that killed him were deliberately
poisoned before being introduced into his meal by political enemies. There are still
cases of mushroom poisoning in many countries today.
There was a newspaper report in Okpokhumi-Emai in Owan East local government
area in 1986 that a family died after eating soup of mushroom. There are many
such reports in the literature all over the world.
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Fig. 1: Reported case of mushroom poisoning (Nigerian Observer, Aug. 1986).
This problem arose and will still arise as long as people depend on collecting
mushrooms from the wild. The practice is fraught with the danger of collecting
edible with poisonous ones.
Be that as it may, our people of old had their own ways of identifying,
differentiating poisonous from edible species. While some edible species are well
known by them, most of the criteria they use are not reliable and in fact are best
described as old wives fables.
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Fig. 2: Collection and identification of mushrooms by rural dwellers.
Some of them are:
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•
Creatures in the wild and domestic animals do not eat poisonous
mushrooms. Not true. Some insects and rodents eat some poisonous
species.
•
That when a mushroom is eaten by insects or slugs or snails, such a
mushroom is edible. That is not true or correct. The body mass of these
animals are not the same with man.
•
Mushrooms loose toxicity after cooking.
•
That when your silver spoon turns yellow when cooking soup with
mushroom, such a mushroom is poisonous. Again this is not reliable as the
type of spoon may vary. Also many Amanita species do not change spoon
colour but are however poisonous.
•
All spring mushrooms are edible.
•
That good odours of some species indicate edibility.
poisonous species without strong odours.
•
Latex – exuding species are poisonous. This is also not reliable. Some
Lactarius species are edible.
There are some
There are many others. These observations among others make many scared about
mushrooms.
Mr. Vice Chancellor, I hope that at the end of this lecture, the audience would have
a better knowledge of what mushrooms are and what they do.
MUSHROOMS: WHAT ARE THEY?
Before the definition, it is important to recall the statement of a prominent Bible
teacher and preacher, Dr Myles Munroe (2001) who made a profound statement
that ‘when the purpose of a thing is not known, abuse is inevitable’. This
explains the misconceptions and abuse of mushrooms over the years. This also
explains the aversion and skepticisms held against mushrooms following their
misuse. It is not uncommon, even in this our contemporary world to hear
phrases like “mushroom school”, “mushroom business” “mushroom church”
etc. It is my sincere wish that after this inaugural, at least I would have
succeeded in reducing these aversions against mushrooms and then begin to
change our attitude towards mushrooms so that we can begin to enjoy God’s
provisions in mushrooms for the benefit of man and development of our Nation.
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CHANGING DEFINITIONS OF MUSHROOMS OVER THE YEARS.
According to Chang and Miles (1992), there are over six different definitions of
mushrooms as follows:
Atkinson (1961) defined mushrooms as belonging to the basidiomycetes and
used the term toadstool as a synonymous term, since there is strictly speaking,
no distinction between a mushroom and a toadstool.
Gray (1967) stated that mushroom is a basidiomycete or rarely, ascomycete
fungus.
Snell and Dick (1971) stated that a mushroom may be edible, poisonous,
unpalatable, tough, etc., but popular usage applies the term to edible ones,
calling the others ‘toadstools’.
Chang and Hayes (1978) defined mushrooms as referring to both epigeous and
hypogeous fruiting bodies of macroscopic fungi.
Pegler (1983) explained that mushrooms and toadstools are terms rather loosely
applied to the fruiting bodies of fleshly gill- fungi, and are commonly used to
denote edible and poisonous species respectively.
Mish (1988) defined it as an enlarged complex aerial fleshy fruiting body of a
fungus (as of the class Basidiomycetes) that consisted typically of the stem,
bearing a flattened cap.
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Chang and Miles (1992) gave the definition that is now universally accepted.
They defined mushroom as a “macro fungus with a distinctive fruiting body
which can be either epigeous or hypogenous and large enough to be seen with
the naked eye and can be picked with hand.”
From this definition, it became clear that mushrooms are found in both
Ascomycetes as well as Basidiomycetes. Thus, they could be aerial, fleshy or
non-edible.
•
The typical structure
Mushrooms exhibit various shapes and sizes ranging from sessile forms to
large globose forms with typical cap stipe (stalk) and root-like structures.
These various forms designate the various groups or taxonomy of the
macromycetes. These shapes are always characteristics of the groups. The
mushrooms present a thing of with their natural shapes.
A typical mushroom has a cap, stipe or stem and a base. Each of these also
has beautiful array of organization that display the wonders of nature.
The Cap:
This part of the mushroom bears the fertile layer- it could be very smooth
with pores or has gills or teeth-like structures. The shape of the cap varies
among the mushrooms which again is characteristic. There are the simple
shaped unbonate, depressed unbonate, oval, etc. The cap could be fleshy
succulent or hard and corky or leathery. Each of these shapes represents a
group of mushrooms.
Fig. 4:Capshapes
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Fig. 5: Cap surfaces
Fig. 6: Gill arrangement.
Fig. 7: Gill spacing
The stipes are also of various shapes and sizes. This variation has become a
taxonomic tool for the grouping of these mushrooms. They range from very tin and
very short to tall and fat forms.
The bases are also of definite forms for each group of mushrooms. There are
bulbous, baggy and rhizoidal forms
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Fig. 8: Stalk/stipe shapes and surfaces.
Fig. 9: Stalk/stipe attachments.
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Fig. 10: Fruit bodies
Array of mushroom forms and shapes as they grow in nature.
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MORPHOMETRY
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A cursory look at the nature of the shapes suggest that there must be a relationship
between the cap and the stipe.
Our studies show that cap: stipe ratio defines this relationship. The higher the ratio
the shorter the stipe with a large or big cap. The reverse is the case i.e. the smaller
the ratio the taller the mushroom with a smaller cap with long stipe. As the ratio
tends to zero the shorter the mushroom and even become sessile (without a
stipe).These parameters are very useful in establishing the candidature of a
mushroom for cultivation. They also help the grower to measure yield. Mushroom
with healthy and large cap with bulky stipe will be more attractive to a grower than
other structures. They could also be used as indices of abnormalities in cultivation
(Okhuoya and Okogbo, 1991).
DIFFERENT SHAPES
The shapes they exhibit show that every shape is significant, from the top –the cap
down to the base of the mushroom. These shapes contribute to the identification of
the mushrooms.
A careful study of mushroom taxa for the past decade revealed a versatility of
mushrooms shapes, sizes and colours that abound in vegetations scattered across
the country. The categorization of mushrooms into morphological groups is
therefore not exhaustive and absolute as structural overlaps or amorphous shapes
are often observed. Therefore, for the purpose of this lecture, I will group
mushrooms, most of which are epigeous, into (i) Umbrella shape, (ii) Bracket
shape, (iii) tuber/bulb shape, (iv) cup and club shape, (v) funnel/fan, (vi) Star
shape/Brush like shape.
(i)
Umbrella-shaped mushrooms
Umbrella shaped mushrooms, commonly referred to as agaric
mushrooms because of their unique cap/stipe configuration are most
diverse, fleshy, gilled, and usually stalked, frail and easily broken at
maturity. Suffice to say that they mostly appear during the rainy season
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and rapidly decline during the dry season. They have intriguing habitat
propensity and are found growing on litter (twigs, leaves, husk, shaft,
etc.), wood (felled logs, tree stumps, living tree or woods in houses),
exposed animal or human dung (coprophilous) and directly on soils
(forest floors, meadows, lawn etc). They also rank among the most
edible, poisonous and ephemeral or deliquescent species of mushrooms
documented in literature.
(ii) Bracket
shaped mushrooms
Coma or circumferential or bracket shaped mushrooms, otherwise
summed up as polypore mushrooms, usually have undersurface pores
with a wide range of textures and mode of substrate attachments. They
may be leathery, papery, woody or corky, rubbery etc. They have textures
that support water retention or minimize desiccation. They may also be
short-stalked or sessile and appear during the rains and subsist through
xerophytic conditions with woody habitat. Many species in this group
are observed all year round.
(iii)
Tuberous and bulb shaped mushrooms
Mushrooms in this category exhibit similar phenological and habitat
patterns with the polypore mushrooms. Their texture is hard or stony or
puffy in the case of bulbous types with a visible sporocarp that lacks
undersurface pores or gills but rather produce spores in a cloudy deposit
on its surface. They are predominant in the dry season.
(iv)
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Cup and club shaped mushrooms
A variety of cup shaped mushrooms have been encountered in many
Nigerian forests and agroforests. They have rubbery to cartilaginous or
papery texture, and may be stalked or sessile; observed growing
gregariously or in a scattered pattern on logs, woods, fallen tree branches,
coarse woods and rarely on twigs, and appearing in various sizes with
cup depth that vary from one species to the other. They may also have
hairy ornamentation.
Unlike the club-forming mushroom, the cup fungi are more xerophytic,
and are found growing on woods of all kinds and limited in species
diversity. They are mainly lignicolous, may be scattered or gregarious.
(v) Funnel/Fan-shaped
mushrooms
Funnel shaped mushrooms are agaric mushrooms with very depressed
cap and possessing decurrent true or false (pseudo- or gill-like ridges)
gills. They are more fibrous and tougher than the umbrella shaped
mushrooms with stalk that may be central, lateral or eccentric or
otherwise absent. In some of the mushrooms placed in this group, the gill
is replaced with teeth-like projections. Their texture is as diverse as the
species ranging from rubbery, papery to leathery with mostly
cartilaginous stipe/stalk and is mostly lignicolous.
(vi)
Star and coral shaped/Brush like mushrooms.
This group of mushrooms was designed to accommodate unique varieties
of mushroom-forming fungi which may be humicolous and/or
lignicolous. They also grow either in solitary or scattered on substrates.
Studies are however still ongoing in identifying and documenting those
present in the Nigeria woodlands.
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It is important to note that in modern terms accurate taxonomic data are better
established with molecular biology methods with the use of PCR.
However micro-morphological features are still useful in the identification of
mushrooms. These features describe the shapes, structures and the arrangements of
the tissues of the different parts of the mushrooms. These include details as to
whether the hyphal systems are monomitic, dimitic and trimitic. The absence or
presence of these systems explains why some mushrooms are bulbous, gelatinous
or leathery etc.
MACROMORPHOLOGY
Cap which comprises of two parts i.e. disc (centre) and margin (edge): size (radius
or diameter in cm or mm), shape of disc (conic, campanulate, parabolic, convex,
plane, umbonate, depressed etc.), shape of margin (enrolled, incurved, decurved,
upturned, straight etc.), surface of cap (dull, shiny, silky, dry, moist, lubricous,
glutinous or viscid; smooth, cracked or wrinkled i.e. laciniated, rimrose,
corrugated, rivulose, areolate etc.), Colour, taste and odor.
Gill attachment (free, seceding, adnate, adnex, sinuate, uncinate, decurrent etc),
spacing of the gills (close, crowded, distant), width of the gills, gill colour, gill
edge and outline of gill edge i.e. eroded, serrate or serrulate),
Stalk dimension (girth or thickness, length), shape of stipe, stipe ornamentations
i.e. glandular dots, lacunary, scabrous punctate, reticulate), stalk interior (hollow or
solid, stuffed or channeled), universal and partial veils.
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MUSHROOM GROUPING
Mushrooms are grouped into four categories:

Edible Mushrooms.
Examples of this group are Agaricus bisporous- the most cultivated
mushroom;
Lentinus
edodes
(shiitake),
Volvariella
volvacea,
Auricularia auricular, Pluerotus squarrosullus, P. tuberregium,
Termitomyces africanus, e.t.c.

Poisonous mushrooms.
Examples are Amanita phalloides, A. verna, A. virosa (the destroying angel)
A. muscaria.

Medicinal mushrooms.
Examples are Pleurotus tuberregium, Lentinus edodes, Schizophylum
cummune, e.t.c.

Miscellaneous mushrooms.
Stereum hirsutum, Phallus indusiatus, Earthstars e.t.c
These groups are not water tight in the sense that there are mushrooms that could
be in more than one category. For example there are edible species that are equally
medicinal.
Mushrooms are in both the Ascomycetes and the Basidiomycetes. The species that
are in the Aasidiomycetes are of very unique shapes. Some are hypogeous i.e.
buried in the soil (the truffles) while others are aerial but with convoluted fruiting
bodies that are succulent (the morels) (Chang and Miles, 2004).
WHERE ARE THEY FOUND
They are found in all sorts of environments. They grow on logs (lignicolous),
animal dungs (coprophylous) agricultural wastes - sawmill dusts, burnt grounds
(pyrophylous), lawns etc.
This explains why they are able to play prominent roles in the recycling of
nutrients. They clean up the floors after man’s ‘mess’ of the environment! They
are in fact the friends of the earth! They are very good recyclers!
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Fig. 11: Lentinus squarrosullus growing on log of wood
Fig. 12: Psathyrella atroumbonata young and matured fruit bodies
Fig. 13: The edible mushroom, Volvariella volvacea on oil palm bunch
Fig. 14: Matured fruiting body of Termitomyces robustus (King of mushrooms) in
the wild.
NUTRITIONAL VALUE
Most Nigerians in the rural areas (65% of population) eat mushrooms. About 90%
of these mushrooms are collected from the wild while the rest 10% is imported in
form of pickled or canned materials usually from Britain, U S A, China and other
countries from the far East (Okhuoya, 1995)
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Compositional analyses of the main cultivated varieties have revealed that, on a
dry weight basis, mushrooms normally contain 19 to 35% protein.
The low total fat content, and the high proportion of polyunsaturated fatty acids
(72 to 85%) relative to total fatty acids, is considered a significant contributor to
the health benefit of mushrooms.
Fresh mushrooms contain relatively large amounts of carbohydrate and fibre
ranging from 51 to 88% and 4 to 20% (dry weight), respectively, for the major
cultivated species (Crisan and Sands, 1978, Okhuoya, 1988b, Okhuoya and
Ayodele, 2007d).
Mushrooms also appear to be a good source of vitamins, including thiamine,
riboflavin, niacin, biotin and ascorbic acid, and of minerals.
Although most fresh mushrooms are 90% water, they can vary in their individual
moisture content, so it’s best to look at them in terms of dry weight. Mushrooms
are rich in protein, very low in simple carbohydrates, rich in high molecular weight
complex carbohydrates (polysaccharides), high in antioxidants, and very low in fat.
They lack cholesterol, vitamin A, and vitamin C. They are a good source of some B
vitamins-riboflavin (B2), niacin (B3), and pantothenic acid (B5) - as well as
ergosterols (which upon exposure to ultraviolet light convert to vitamin (D2).
They’re high in dietary fiber, with edible varieties ranging from 20 percent fiber
(by dry weight) for Agaricus species (such as button mushrooms) up to 50 percent
for Pleurotus species (such as the phoenix oyster). Mushrooms are good sources of
essential minerals-especially selenium, copper, and potassium-elements important
for immune function and for producing antioxidants to reduce free radicals.
Mushrooms also contain numerous medicinal compounds such as triterpenoids,
glycoproteins, natural antibiotics, enzyme inhibitors that fortify health.
MUSHROOM NUTRICEUTICALS.
The public has become more and more concerned about their health and nutritional
matters in recent times. This has sparked off the commercialization of natural
foods consumed as dietry supplements. Chang and Miles(2004) came up with the
new mushroom vocabulary “mushroom nutriceuticals” as extractable dietry food
supplements from either the fungal mycelium or the fruiting body of the
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mushroom. Due to nutritional and medicinal contents of some mushrooms, it is
now recommended to fortify foods with mushrooms e.g. mushroom bread, rice etc.
There are so many mushroom supplements in the herbal markets especially in
Europe, Asia and America. Many have been associated with treatment of ailments.
Fig. 15:Mushroom tea
Fig. 16: Mushroom supplements
Fig. 17: Mushroom products and Nutriceuticals
THE NIGERIAN EXPERIENCE WITH MUSHROOMS
Africans generally are known to be mycophagists. They, however for a very long
time, depend on collecting these mushrooms from the wild. This practice is fraught
with the dangers of mistaking poisonous for edible ones. As a result there are many
reported cases of death due to mushroom poisoning. This explains why many today
have aversions against mushrooms.
However a close look at the traditional farming system reveals that there has been
a place for mushroom production in the country (Okhuoya, 1997).
Traditionally, there are different ways by which our people have consistently
maintained an interest in mushrooms.
In some parts of the country the local population do the following to produce
mushrooms
Site preparation
This involves taking proper note of the site of occurrence of a mushroom in the
growing season (mostly rainy season) such sites are regularly visited for mushroom
harvest. The area is protected either by fencing or ring weeding such that it is
isolated from other parts of the farm or the forest.
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The site is visited each growing season (usually in the rainy season) for mushroom
harvesting. The practice is commonly associated with Termitoyces spp, commonly
referred to in the Nigerian tradition as “King of mushroom” a very delicious
mushroom. Such a harvest is equated to killing a precious bush meat which is
“slaughtered” and eaten by the entire members of the extended family system.
Some Coprinus spp. are also harvested in that way.
These sites produce mushrooms from season to season. This obviously has
limitations on yield. The yield from this practice is not improvable and it depends
entirely on the variable natural environmental conditions of that season which are
not controllable.
Log Preservation
As in the site preservation above, logs known to grow particular edible mushrooms
are cut and placed under shades and watered regularly. Mushrooms from these
logs are harvested from one season to the other. This method appears to be the
nearest to the cultivation of mushrooms in modern times. Auricularia spp and
some Pleurotus spp have been produced with this method.
Soil burial of mushroom Sclerotia
Pleurotus tuberregium (Fr) Sing. produces sporophores and sclerotia when in a
suitable environment. Both the sclerotia and the fruitbodies are edible. The
sclerotia which are normally harvested from the bark of decaying wood or buried
wood are used for many purposes including medicinal uses.
They are buried in soils under shade or a cool place. After 5-10 days the sclerotia
start producing fruiting bodies in flushes which are harvested and eaten by the
local people. This appears to be the only real traditional method of cultivation.
This method again has problems of soil pathogens of the sclerotia. The sclerotia
get easily attacked by soil pathogens like nematodes and rodents.
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Traditional mushroom Preservation
Collection of mushrooms from the wild by the people is usually in the rainy
season. The unused ones are preserved by some traditional methods listed below:
Drying: This process is usually done in two ways:
Sun drying:
This involves direct use of solar energy.
i.
The mushrooms are laid out on a mat in an open place that allows maximum
exposures to direct sunlight and heat. Drying in this manner is continued until
the mushrooms are very dry. They are then stored away or used as the need
arises or sold in the market.
Smoking
Here, the mushrooms are placed in a cage made from wire mesh. Usually, the
cage is hung few feet above the traditional tripod for cooking. It is left there as
long as necessary until the mushrooms are dried. The regular heat/smoke from
the coal fire gradually dries up the mushrooms. Smoked mushrooms taste
better than the sun dried ones.
ii.
Mushroom species studied
Their cultivation.
A close study of their growth in nature has helped researchers to develop various
ways of growing mushrooms in the laboratory which eventually led to their
commercial cultivation.
•
Mushroom cultivation generally involves the following steps:
(a) Bed preparation
(b) Spawning (mushroom seed planting)
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(c) Casing
(d) Picking or harvesting
(e) Packaging/Preservation
Each of these steps requires careful handling for the best results. Not all
mushrooms go through these steps before fruiting. However Agaricus
bisporus, the world most cultivated mushroom goes through all the five
steps outlined above.
The major difficulty of growing mushrooms is that of having to work out
specific recipes for different species of mushrooms. No one method applies
for the cultivation of all mushrooms. Some mushrooms have not been
successfully cultivated in the laboratory e.g Termitomyces sp, the ant hill
mushroom. Only the ants know the secret of growing this delicious
mushroom!
Without going into much detail of the different steps or procedures for the
cultivation of these mushrooms, each of the steps requires very careful
approach to get the best results. The step that all mushrooms must pass
through before fruiting however is bed or substrate preparation (Okhuoya,
2000).
The quality, type and nature of the substrate determine the quality, quantity
and type of mushrooms that are produced on such a substrate. The prevailing
conditions in the substrate affect the growth of the mycelium of the
inoculated mushrooms.
Mushroom ‘running’ in the substrate can be hindered if for example the
substrate temperature is above or below the optimum. Much compactness of
the substrate can also make the mycelium develop fast. Good ventilation of
the medium is also necessary as low oxygen and high carbon dioxide slow
down mycelia growth in substrates (Oei, 1996, Okhuoya, 2008). These and
other factors must be considered for good substrate preparation. Mushroom
substrates are made from different materials. Traditionally mushrooms were
25
grown on horse manure until the Second World War when horses were in
short supply. Scientific investigation then followed after the war in search of
appropriate substrate as substitute for horse manure for the cultivation of
mushrooms.
The works of Badcock (1941) and Papazian (1955) pioneered the search for
mushroom substrate. The choice or prominence of any substrates in any
region or country appears to depend on the availability of such substrates in
that region e.g. paddy straw from rice common in Asia for cultivating paddy
straw mushroom (Volvariella volvacea).
Generally, substrates used in the cultivation of mushrooms are derived
mainly from agricultural and industrial wastes. The utilization of such
wastes has a direct contribution to solving the global problem of
environmental pollution (Zadrazil,1977).
There are many substrates for mushroom cultivation.
In Nigeria, as in other parts of Africa, these raw materials have not been
fully exploited for mushroom cultivation. A close look at the habitat of wild
mushrooms indicates that they are normally found on such sites of natural
wastes due to senescence (e.g. on leaf litter, fallen logs) or on wastes
accumulated on sites of cottage or farm processing of agricultural products.
This common observation indicates the potentials of such wastes for the
cultivation of mushrooms (Okhuoya, 2000, Okhuoya etal., 2010).
In Nigeria many species of mushrooms are popular and acceptable to the
people, which they collect from the wild, either from the forest floor or
grassland in the rainy season (April to September). They cook and use them
for various soup preparations or are sun-dried or smoked for preservation.
Mushroom hunting used to be a popular hobby among the village youths
who use it as a source of income. Many edible species have been described
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and identified in Nigeria (Oso, 1975, 1977, Zoberi, 1972, Isikhuemhen and
Okhuoya, 1995, and Okhuoya, 1995)
Auricularia auricular:
This jelly mushroom is eaten by many of the local people in the rural areas. They
are traditionally collected on wet logs in the woods during the rainy season or on
logs under shades in the forest. The technology for its commercial production was
developed in Asia where its consumption is very popular. In our laboratory log
inoculation method has proved very successful in producing fruiting bodies. In
this method, dry logs of rubber (Hevea brasiliensis) and oil palm Elaeis guineensis
are drilled to form cavities of 1inch deep and 1inch diameter and 6 inch apart.
These logs are soaked in water for about three to four days and then air dried for a
day. The cavities are then plugged with mycelia spawn and placed under a shade
and watered every day. Mushrooms begin to appear on the log surfaces after about
21 days of inoculation. The mushrooms degenerate if not preserved either by
drying or pickled.
Volvariella volvacea
Fig. 19: Volvariella volvacea cultivated on banana leaves
This mushroom is a tropical species. It grows easily on rice, sorghum and wheat
straw. Other substrates like the wet palm fruit fiber and cotton wastes have been
used to cultivate them (Chang, 1993, Zoberi 1972, 1973, Oso 1975, 1977,
Okhuoya 1993, Akpaja et al., 2005).
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The major problem with their cultivation is their poor shelf life. They degenerate
very fast if not used within two days after harvest. They are however, very easy to
cultivate with a short cropping period of 14 days.
Lentinussquarrosullus
Fig. 20: Lentinus squarrosullus cultivated on sawdust.
This is a popular mushroom among our people. It is highly accepted for its “fish”
taste when dried. Log inoculation method has been very successful in its
cultivation. Locally adopted technology was developed at the Rubber Research
Institute of Nigeria (RRIN) Benin City. In this method, rubber logs are inoculated
with saw dust spawn and then layered in mature rubber plantation, producing the
necessary shade and humidity.
This practice is being recommended for rubber farmers as an inter-cropping
system. This mushroom is highly recommended for farmers as it is very cheap to
cultivate and has good shelf life and could also easily be dried and stored. It is also
possible to cultivate this mushroom on the sawdust of many economic trees
processed in our sawmills (Oghenekaro etal., 2007).
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Psathyrella atroumbonata:
Fig. 21: Psathyrella atroumbonata cultivated on wood chips.
This mushroom is a very fast-growing mushroom on logs and tree stumps. The
local people harvest and sell in local markets. However, it has poor storability and
deteriorates within 24 hours. It has been successfully cultivated in our laboratory
using banana leaves. The technology is being recommended to our people
(Ayodele and Okhuoya, 2007a, 2007b, 2007c, 2007d).
Pleurotus tuberregium:
Fig. 22: Fruit bodies of Pleurotus tuberregium.
29
Fig. 23: Sclerotia of Pleurotus tuberregium.
This mushroom is found in many parts of tropical Africa. It grows naturally in the
wild on logs, leaf litter, on forest floors, and buried wood (Okhuoya, 1993, 1995,
Okhuoya and Okogbo, 1990, 1991, Isikhuemhen and Okhuoya, 1996). The
sclerotia and the sporophores are edible and very well accepted by the local
population. The cultivation of this mushroom commercially has become very
important because of its various applications in the West African Sub-region. In
Nigeria, the sclerotia are edible and used also for medicinal purposes. It is
commonly used by our tradomedical practitioners (Osaguelekhor and Okhuoya,
2005). Some make paste of it and rub their faces helping them to see into the future
as they claim. It’s widely used by our people especially in the eastern part of the
country to make egusi like soup (Akpaja, et al., 2003). The situation is different in
Ghana where the sclerotia are only used for medicinal purposes and fattening of
malnourished babies (Leslie 1993 personal communication).They rub these babies
with the paste and within few weeks they begin to gain weight. This phenomenon
is not yet understood which needs investigation.
Most studies carried out in my laboratory have concentrated on how best to
cultivate the fungus. The results of such studies have been published in several
journals. The reports are summarized as follows:
30
A.
a.
Sporophore Production
Spawn Preparation: Many materials have been tested but only oil palm fruit
fiber proved to be the best for this purpose. Okhuoya and Okogbo, 1991,
Okhuoya and Etugo, 1993, Isikhuemhen and Okhuoya, 1995, Ayodele and
Okhuoya, 2008).
b.
Size of sclerotia used and yield: It is established that the larger the
sclerotum used for “planting”, the higher the yield. (Okhuoya and Etugo
1993, Okhuoya, 1995, Okhuoya et al., 1998).
c.
The back of the sclerotia is usually peeled and discarded. These peelings
have been found to be useful in equally propagating the fungus, showing
that the power to initiate growth from the sclerotium is not limited to the
back of the sclerotium. (Okhuoya and Etugo, 1993, Okhuoya and Okogbo,
1990).
d.
The sporophores of the fungus do better with natural pigmentation when the
soil or substrate of cultivation is watered rather than being aerially watered
sprayed (Okhuoya and Ajerio, 1988a).
e.
The fungus can develop abnormal fruits in high relative humidity (+96% and
high CO2 (Okhuoya, 1995).
B.
Cultivation of edible sclerotia
Laboratory induction:
Sclerotial induction has been tested for the
production of sclerotia in the laboratory. Drill dusts from logs of oil palm,
(Elaeis guineensis, Jacob) Daniella oliveri. (Rolfe) Hutch and Dalz, have
been successfully used to produce sclerotia. (Okhuoya and Okogbo, 1990).
Fig. 24: Emerging sclerotia of P. tuberregium in soil
Fig. 25: Formation of sclerotia of P. tuberregium on dead wood
Agricultural wastes from Zeamays (Corn): n Manihot esculenta (cassava) and
sawdusts have also been used to produce sclerotia. Pilot experiments in a large
scale on sawdust have demonstrated clearly the success of this technology for the
production of the edible sclerotia at commercial level (Isikhuemhen and Okhuoya,
1995, Okhuoya, 2000b, Okhuoya et al., 2000, Okhuoya et al., 2010, Okhuoya and
Harvey, 1982a, Okhuoya and Okogbo, 1990, 1991).
31
Fig. 26: Agro-industrial wastes for mushroom cultivation.
Log Inoculation Method
This method has also proved very successful for the production of edible sclerotia
of this mushroom. This technique is very successful with logs of D. oliveri and E.
guineensis. The sclerotia formed with this method are always few cm away from
points of inoculation on the logs, buried within the wood bark and the hard wood
(Okhuoya and Etugo, 1993, Okhuoya, 1997, Okhuoya, 2000).
MUSHROOM STORAGE AND PRESERVATION
Mushroom Preservation
Mushrooms continue to respire after being harvested. Their rate of respiration is
comparatively higher than those of other fresh products. If unchecked, this afterharvest respiration results in changes in the colour, taste and texture of mushrooms.
All these put together results in lowering the quality of the mushroom.
As the texture and other qualities of the mushrooms drop, there is a concomitant
increase in the number of bacteria and fungi which would further work on the
mushroom and deteriorate it eventually. From the fore-going, it can be seen that
mushrooms are either marketed fresh as soon as harvested or preserved by
whatsoever means as quickly as possible.
The storage of mushrooms broadly falls under two forms. These are the short-term
and long-term storage methods.
SHORT –TERM STORAGE
1.
32
The freshness of mushrooms can be extended after harvesting by
refrigeration at 1-4˚C. Cooling of the mushrooms under refrigeration, results
in the reduction of the metabolic activity of the mushrooms thereby making
it possible for the mushrooms to remain fresh for up to two weeks. To
effectively preserve mushrooms therefore, they should kept cooled with
storage temperature of 0 - 2˚C within five hours of picking.
Sun-drying, especially in the tropics during the dry season, is also another effective
method of preservation. It is equally advisable to sundry as soon as harvested.
Drying such mushrooms on a clean metal sheet is preferred.
Fig. 27: Packaged mushroom products in a British supermarket.
LONG TERM STORAGE
Under this category, many methods are employed depending on one’s economy
and acceptability by consumers. Drying, canning, bottling, picking are the methods
used in this category.
Drying: this method can be sub-divided into two namely: sun drying and thermal
power drying. Essentially, drying preserves mushrooms by removing enough
moisture to inactivate other enzymes and micro-organisms. Dried mushrooms have
a good flavor thereby imparting a unique taste and aroma to prepared foods.
After drying, the mushrooms tend to absorb moisture from the air. If the moisture
content increases to 20%, the mushroom may be attacked by insects and molds.
Therefore the dried mushrooms should be put into polyethylene bags, sealed and
kept in a dry, cool and dark place at 2-5˚c.
Canning and Bottling
Several basic steps are involved in this case. They include: cleaning, blanching,
canning, sterilization, cooling, labeling and packaging.
33
After cleaning, an appropriate level of ascorbate is incorporated for color retention.
Rinsing then follows after which they are blanched for about 2 minutes. Blanching
helps to inactivate the enzymes. After adding some quantity of sodium chloride
(2.5%) and citric acid (0.5%), the cans are then sealed and sterilized. Sterilization
is followed by cooling in a large volume of water in a sink. Bottling follows the
same procedure as canning but requires much less instrumentation. It can therefore
be adopted by small-scale growers without much difficulty.
PICKLING
In this process, the mushrooms are cleaned, sorted and washed. Slicing into desired
size is not uncommon. Blanching with 3% salt water for three to four minutes is
recommended. Thereafter, draining of water is followed by dipping in cold water
immediately. They are then transferred to a jar or bottle and brine (22% salt) is
added with a little vinegar, sugar and other spices .Citric acid can also be added.
The jars are then loosely closed and steamed for one hour. The lids are tightened
when cooled and the contents chilled before eating.
PROBLEMS ASSOCIATED WITH MUSHROOM CULTIVATION
Mushrooms like other cultivated vegetable crops are subject to attack by pests and
pathogens (Hayes and Nair, 1975, Okhuoya and Okogbo, 1991). The visible illeffects of handling, sorting and careless packing are very common with
mushrooms as with other perishable crops. Most mushrooms are lost due to pests
which could either cause actual fruit decay or cause disfigurement and consequent
lowering of the amenity value. These include slugs and fungi.
Sclerotium rolfsii, a soil pathogen was found to be pathogenic to the fruiting bodies
of Pleurotus tuberegium causing stipe rot (Okhuoya and Okogbo, 1990, Okhuoya
et al., 1996). This can be controlled by screening the soil using cocoyam petiole
bait as described by Ikediugu and Osunde, 1977). A good sanitary condition in the
mushroom house is vital in the control of these pests. Also good harvesting
procedures and excellent packaging systems enhance quality mushroom sold to
consumers.
34
MUSHROOMS: WHAT THEY DO.
•
Their spore production.
Mushrooms produce astronomic amounts of spores. Buller pioneered the
studies of the spore production of agaric mushrooms (Buller, 1909). These
earlier studies were followed by Ingold, (1960) with more of the lager fungi.
There are many reasons adduced why higher fungi produce large amount of
spores at any one time: for survival and the increase of the probability of at
least some of them getting to susceptible host for growth to continue their
cycles (Kramer, 1970)
Majority of these fungi produce their spores at night (Ingold, 1979, Okhuoya
and Harvey, 1982). Most fungi in general, discharge their spores at night as a
means of avoiding the deleterious effect of the sun’s radiations during the
day (Rockett and Kramer, 1974). Basidiomycetes generally produce very
large numbers of basidiospores which are less viable than many other
spores. They compensate for this poor survival through the development of
perennial mycelium which can become extensive, capable of supporting
large sporocarps over comparatively long periods of time. Some mushrooms
produce spores over a short period and die. Such fungi have very short life
span. This is common with the fleshy and succulent Agarics. In this category
are the Mycena, Agaricus and Pholiota spp. On the other hand, the corky
polypores are perennial in their spore production and hence they have long
life span. In this group are the Ganoderma and Daldelea spp.
Spore production in fungi falls into two forms - active and passive spore
production.
In the active spore discharge the fungus has an inbuilt mechanism that sets the
process in motion once the spores are mature: the mature basidiospores in most
cases have Buller’s drop which aid in their projectile release of the spores that get
dispersed through some other agencies. In case of passive production, the matured
spores fall directly on the same substrates of the parent. They could be further
dispersed through the agencies of wind or animals.
35
Spore Discharge Rhythms in selected Mushrooms.
Both laboratory and field studies of spore discharge in basidiomycetes show them
to be mostly nocturnal (Sreemalu, 1959, Haard and Kramer, 1970, DeGroot, 1968,
Rockett and Kramer, 1974b, McCracken, 1970, Okhuoya, 1981).
However few studies have been done to determine whether these are exogenously
or endogenously controlled. Kramer and Long (1970) found that certain species of
Ganoderma applanatum exhibited a pattern of spore discharge with peaks at 9-10h
intervals under continuous temperature and relative humidity, and also either under
continuous light or dark (Okhuoya, 1988b, Okhuoya and Harvey, 1982b).
FIG. 28: Diurnal variations of spore discharge in selected basidiomycetes.
Walkey and Harvey, (1967) defined an endogenous rhythm of spore discharge as
one which persists even when the influence of external rhythmic agencies, such as
alternations of light and dark, is interrupted over extended periods of time. On the
other hand, they referred to exogenous rhythms as those that respond to and
synchronize with rhythmic agents in the external environment. Endogenous
rhythms have been described in a number of ascomycetes, e.g. in Daldinia
concentrica (Ingold and Cox, 1955), and Sordaria macrospora and Lopadostome
turgidum (Walkey and Harvey, 1967). Similar studies have not been well
established in the basidiomycetes, apart from work of Kramer and Long, (1970) on
Ganoderma applanatum.
In my study (Okhuoya, 1989) on the effect of light on spore discharge of some
basidiomycetes, I found that following entrainment of nine selected species of
basidiomycetes with alternating 12 h light and 12 h dark periods, circadian rhythms
with nocturnal peaks of spore discharge were found to persist in continuous
entrainment, Piptoporus betulinus, Panellus stipticus, Auricularia auricular and
Dacrymyces deliquescens made immediate readjustment with peaks of spore
discharge synchronized with the new dark time periods, while Ganoderma
applanatum and Trametes betulina took 48 h to readjust. These reactions indicate
exogenous rhythms (Fig. 29).
36
Fig. 29: Periods and duration of peak spore discharge of test fungi under light and
dark within 96h after entrainment. 0h = 12.00 a.m. Bars represent periods and
durations of peak spore production of the fungi.
Pattern of spore discharge over hymenial surfaces
Spore prints of certain basidiomycetes, especially the agaricales, are commonly
used by mycologists for taxonomic purposes. They are useful in the study of gill
arrangement and spacing. Buller (1909) observed that radiating lines in a spore
deposit under an agaric sporophore correspond to the spaces between the gills.
Gregory (1979) in his studies on the detailed structure of the agaric spore print or
spore bands observed that the resulting spore lines are not uniformly dense. Each
spore line is much denser near the edge thus giving it a much “firmer” outline.
Buller (1922) observed the mottling of gills in Panaelus campanulatus. He found
that the areas with more advanced spore-bearing basidia are relatively darker than
those with less advanced spore bearing basidia. He further observed that the sum
of the darker areas always exceeded by a considerable margin, the sum of the
lighter areas.
•
Apart from these observations there is virtually no information in the literature to
the pattern of spore production over the surface of the hymenium.
Some of the questions that needed to be answered regarding the pattern of spore
discharge over the surface of the hymenium included:
a)
b)
Is spore productivity over the whole of the hymenial surface uniform?
If there is variation in productivity is it associated with variation in age of
different areas of the hymenium?
I then attempted to answer these questions by investigating the pattern of spore
production over hymenial surfaces of some basidiomycetes.
My result showed that considerable variations in spore productivity were detected
within the area of single hymenial surfaces of certain polypores (Okhuoya, 1988a).
The hymenium has in irregular pattern, areas of low as well as high spore
production, common both in the periphery (young) as well as in the inner (old)
part. These were recorded as isospore diagrams showing that the basidia all over
the hymenia are at different stages of development.
37
Fig. 30: Variations in spore density in Piptoporus betulinus fruit and Coriolus
versicolor fruit respectively
ROLE OF MUSHROOM IN MYCOMEDICINE
It is now no more news that fungi play key roles in treating maladies affecting the
health of humans and animals. The first insight into this fact was the discovery,
during the Second World War that Penicillin from a fungus, Penicillium notatum
could stop the growth of some disease causing organisms (Hamond and Lambert,
1978). Back then, it was regarded as the wonder drug because it came handy for
the treatment of soldiers wounded in battle with infections.
Consequently, upon the discovery of the wonder drug, there was a very strong
drive for studying the antibiotic effects of substances released from many bacteria
and fungi. This search, for what will cure our diseases continues to this day.
Mr. Vice Chancellor Sir, this reminder of what transpired in the 40’s is to enable us
focus on the present and future.
In this present time, there is the need for us to quickly, as a matter of urgency
document the indigenous knowledge and uses of fungi by our people. From such
information, it will be possible for us to conduct basic and applied research into
authentication of the people’s claims.
At this juncture, it may be necessary to cast our minds to the situation in China
where Ganoderma species has been used for over a millennium by tradomedical
practitioners. The Chinese people have been using the mushroom to cure very
serious ailments. The empirical confirmation did not occur until some three
38
decades ago. Now, the fungus is known to have anti diabetic, anti-cancer and
hypocholesteroemic activity along with other properties. The claims by our own
Nigerian tradomedical practitioners on the uses of some mushrooms largely remain
to be confirmed in the laboratory. The nutrient contents and secondary metabolites
as shown in Table 2, may give a clue to the medical effects they will elicit.
A number of ailments are being treated tradomedically using some mushrooms
(Osaguelekhor and Okhuoya, 2005, Akpaja et al., 2003, Ihayere et al., 2010). Who
knows if all the tradomedical claims are in correct? This is one of the reasons why
we have now intensified efforts in our laboratory to empirically confirm the
authenticity of such claims. The results are very promising.
Table 2: Some edible and medicinal mushrooms in Nigeria analyzed for toxins,
secondary metabolites and other nutritional contents.
Mushroom
Nutritional
content
Toxin
Auricularia
auricular
Judae (Bull.) Quēl
+
-
-
Calvatia
cyathiformis
(Bose.) Morg.
+
-
-
Chlorophyllum molybditis
(Mayer ex. Fr.) Massee
-
+
+
Cortinarius melliolens Fr.
-
+
+
Lentinus subnudus Berk.
+
+
-
Lactarius trivialis Fr.
+
-
-
Pleurotus tuberregium (Fr.)
Singer.
-
+
+
Psathyrella atroumbonata
Pegler
+
-
-
Schizophylum commune Fr.
+
-
-
Termitomyces microcarpus
(Berk and Br.) Heim
+
-
-
Termitomyces robusta
+
+
+
39
Secondary
metabolites
(Beeli) Heim
Tricholoma lobayense
Heim
-
+
-
Volvariella esculenta
(Mass) Singer.
-
+
+
(Source: Okhuoya, et al., 2010)
Since antiquity reference has been made in all cultures to the use of moulds to treat
wounds infected with bacteria (Wainwright, 1989). Such ‘mould therapy’ has in the
past been regarded as scientifically unfounded folklore. However, there is good
evidence to suggest our ancestors maintained cultures of therapeutically active
mould or knew how to select for their growth. These cultures were then used to
treat wounds infected with bacteria, and even cured established surface infections.
Many species of medicinal mushrooms have been used in folk medicine for over a
millennium. The use of medicinal mushrooms in folk medicine is best documented
in far East. Medicinal mushrooms are now the subject of study for many
ethnobotanists and medical researchers. The ability of some mushrooms to inhibit
tumur growth and enhance aspects of the immune system has been a subject of
research for approximately fifty years. International mushroom research continues
today, with a focus on mushrooms that may have hypoglycemic activity, anticancer activity, anti-pathogenic activity and immune system enhancing activity.
In the past decade mushroom researchers have increased the body of knowledge
which led to the establishment of International journal of medicinal mushrooms.
Recent research has found that the oyster mushroom naturally contains cholesterol
drug lovastatin. Mushrooms produce large amounts of vitamin D when exposed to
UV light. Some antibiotics have been isolated from some mushrooms (Table 3).
Table 3: Isolated antibiotics from selected mushrooms
40
Mushrooms
Antibiotics
Armillaria mellea
Armillaric acid
Fometopsis officinalis
Agaricin
Agaricus campestris
Campestrin
Calvatia gigantia
Calvacin
Coprinus species
Coprinol
Trametes versicolor
Corolin
Lentinus edodes
Cortinellin
Ganoderma lucidum
Ganomycin
Sparassis crispa
Sparassol
Schizophyllum commune
Schizophyllan
(Source: Stamets, 2005)
Numerous higher Basidiomyces are important sources of medicinal substances
used in the treatment of a wide range of diseases. Traditional use of mushrooms as
medicine has been long established among different cultures of the world. In the
far East countries, especially in China, Japan and Korea, mushrooms have long
been revered for their curative attributes (Wasser, 2005). In Nigeria, many
mushrooms have been used in the treatment of diseases by our people.
There is information in our cultures on the use of mushrooms in traditional healing
practices as documented by Isikhumhen and Okhuoya, 1995, Akpaja et al., 2003,
Akpaja et al., (2005) Oso, 1975, 1981, Alabi, 1994, Jonathan and Fasidi, 2005,
Jonathan et al., 2007, among others. These authors have reported some higher
fungi that possess important medicinal ingredients used for treating diseases such
as high blood pressure, pneumonia, urinary tract infection, intestinal disorder by
Nigerian herbalists. These mushrooms include Ganoderma lucidum, Fomes
fomentarius, Daldinia concentrica, Calvatia species, Termitomyces species,
Lycopendon, polypores, Psathyrella atroumbonata, Schizophyum commune,
41
Corilopsis occidentalis, Auricularia spp. (Jonathan and Fasidi, 2005, Oso, 1977).
Jonathan (2005) showed that the antimicrobial potency of puffballs (Lycopenndon
sp and Calvatia spp.) could be compared to some extent with the commonly used
antibiotics.
In Northern Nigeria wild Ganoderma lucidum was used in treating Elmeria tenella
(coccidian) infected broiler chickens. Like procaine penicillin, G. lucidum extract
shows activity that promotes wound healing by way of accelerating epithelial and
collagen tissue formation (Ogbe et al., 2008). Also, Ofidile et al., (2005), showed
the antimicrobial effects of a colossolactone E and colossolactone (2, 3hydroxylcolossolactone E) isolated from G. lucidum active against Pseudomonas
syringe and Bacillus substilis. The zones of inhibition of colossolactone E were
found to be similar to those of chloramphenicol. The findings of Ogbe et al., 2009,
showed that the wild Ganoderma species aqueous extract like procaine penicillin
has activity that promotes wound healing by way of accelerating epithelial and
collagen tissue formation.
Many fungi are used by the native doctors for spiritual purposes (Akpaja et al.,
2003, Akpaja et al., 2005, Dania, 2010, Okhuoya and Akpaja, 2005, Osagualekhor
and Okhuoya, 2005,). Termitomyces microcapus is one of the ingredients used for a
concoction that renders the victim impoverished. T. robustus is used in preparation
of charms for good luck, and remedy for migraine. The stinkhorns are used for
curing leprosy. Puffballs are used for the cure of pneumonia while Daldinia
concentrica is used for the remedy of leucorrhoea. Phallus, Dictiophoras,
Mutinus, Coprinus ephemers, Clathrus kalchbrennerra, e.t.c. are used in the
preparations for curing leprosy and the making of harmful charms by Yoruba
traditional doctors (Oso, 1981). Pleurotus tuberregium is used for treating ailments
such as headache, stomach pain, fever, and cold (Isikhuemhen, 1995).
The Urhobos use the sclerotium for the treatment of chest pain, dropsy, and
smallpox. The Ibos native doctors use it for treating asthma and controlling high
blood pressure and nervous disorder. The Hausa fortunetellers use the infusion of
the sclerotia and herbs for washing their faces (Oso, 1981). Sclerotia of Pleurotus
tuberregium are combined with different herbs to treat whooping cough, dysentery,
malaria fever and energy-providing food for pregnant women and babies suffering
from malnutrition and ear infection in children among the Esan and Akoko-Edo
42
people (Osagualekhor and Okhuoya, 2005, Dania, 2010). Investigations of
bioactive metabolites and medicinal properties of mushrooms play an important
role in the development of new biotech products and biopharmaceuticals. Most
mushrooms contain polysaccharides like alpha and beta glucans that form the basic
components of modern drugs.
Table 4: Indigenous uses of mushrooms by the Akoko-Edo people
and the Binis.
Mushrooms
Local name
(Akoko-Edo)
(Bini)
Uses/Disease
1
Daldiniasp.
and
Ganoderma
Sp.
Ushumu
Emunomuer
oshu/Ushumu an
ota
Pregnancy
problems, bad
sight
2
Daldiniasp.
Ushumu oshi
Emunomuer
an
Pile, saw,
wound
3
P.
tuberregium
Ufushumu
Uhenrun
Rheumatism,
Measles, Body
rashes,
Stomach, head
problems and
Malnourishmen
t in children
4
Ganoderma
and P.
tuberregium
u.
ota/ufushum
u
Ushumu
ota/Uherun
Barrenness/Infe
rtility, chest
pain
5
Schizophyllu
msp.
Ushumu ota
Peperu
Skin Infections
6
Lactarius sp
Ushumu
Not given
Ulcer
43
arogbo
7
Coprinus sp
Ushumu iku
Not given
8
Ganoderma
Oshu/
Not given
ushumu osha
Ear infection
Chest pain
(Source: Dania, 2010, Akpaja et al., 2005)
WASTE UTILIZATION BY MUSHROOMS
Mushrooms can degrade virtually any lignocellulosic waste. This is essentially due
to their possessing the enzymes that can degrade these materials. Fortunately for
us, all agricultural wastes fall into this category. These wastes contain Lignin,
cellulose and hemicelluloses as their major components. This is in addition to other
substances such as pectic substances and many secondary plant metabolites. Fungi,
in company with bacteria, are the major dissemblers of complex organic
substances. It is the continuous bio-conversion activities of these organisms that
ensure that nutrients are not locked up in plant and animal remains. Fungi have the
ability to penetrate substrates with the aid of their hyphal tips.
Looking around our environment today, we see a lot of wastes including, domestic,
industrial and agricultural wastes littering everywhere. The disposal and
management of these wastes is a major challenge. Mushrooms can play a major
role in solving this problem.
44
•
MYCOREMEDIATION
•
This is the use of fungi to degrade or remove toxins from the environment.
Fungi are known as molecular dissemblers, breaking down many
recalcitrant, long-chained toxins into simpler, less toxic chemicals.
Mycoremediaton also holds promise for removing heavy metals from the
land by channeling them to the fruit bodies for removal. The practice
involves mixing mycelium into contaminated soil, placing mycelia mats
over toxic sites, or successive treatment. Many mushrooms can hyper-
accumulate heavy metals like Arsenic, Cadmium, Copper, Lead, Mercury
and radioactive Cesium and Selenium.
45
•
The powerful enzymes secreted by certain fungi digest lignin and cellulose,
the primary structural component of wood. These digestive enzymes also
break down a surprisingly wide range of toxins that have chemical bonds
like those in wood. Such mushrooms can be classified into two groups viz;
brown rotters and white rotters. Brown rot fungi’s extracellular enzymes
break down the white, pulpy cellulose, leaving behind the brownish lignin
(hence the name). These fungi cause checkered cubical cracking and
shrinking in wood. Examples of brown rot mushrooms are multicoloured
polypore (Lenzites betulina), large Lentinus (Lentinus ponderosus), Sulphur
tuff (Laetiporus sulphureus and Laetiporus conifericola), splitgilled
polypore Schyzophyllum commune), agarikon (Fomes officinalis), and dry
rot house wreckers (such as Serpula lacrymans and Serpula himantoides)
•
White rot fungi, more numerous than brown rotters, produce enzymes that
break down the recalcitrant brown fibre in wood, leaving the cellulose
largely intact, thus giving the wood a white appearance. The oyster
mushroom (Pleurotus ostreatus), maiitake (Grifola frodnosa), turkeytail
(Trametes versicolor), reishi (Ganoderma lucidum), artist conk (G.
applanatum), and crust fungi (Phanerochaete chrysosporium) are among the
more powerful white rot mushrooms. Some species of mushrooms produce
both types of rot, leaving a mottled white and brown discoloration in the
wood. Examples are Hericium abietis and Hypholoma capnoides.
•
White rot mushrooms are mycoremediators of toxins held together by
hydrogen-carbon bonds. Enzymes secreted by this group’s mycelia include
lignin peroxidase, maganase peroxidase and lacases (Schleiphake et al.,
2003). Only white rot mushrooms seem to produce manganese-dependent
peroxidase, an enzyme that mineralizes wood and is particularly efficient in
breaking hydrogen bonds. Lignases and cellulosic enzymes are also
produced by the mycelium of the white rot fungi.
•
These complex mixtures allow the mycelium to dismantle some of the most
resistant materials made by humans or nature. Since many of the bonds that
hold plant material together are similar to the bonds found in petroleum
products, including diesel, oil and many herbicides and pesticides, mycelia
enzymes are well suited for decomposing a wide spectrum of durable toxic
chemicals. Because the mycelium breaks the hydrogen-carbon bond, the
primary nonsolid byproducts are liberated in the form of water and carbon-
dioxide. Table 4 shows some mushrooms with activity against chemical
toxins.
Table 5: Mushroom with Activity against Chemical Toxins
BZ
Dioxi
ns
PC
Bs
Grifolafrondosa
X
Lentinus edodes
X
Phanerochaete
chrysosporium
X
Pleurotus ostreatus
X
PENTA
s
X
PAH
s
X
X
X
X
X
Psilocybe spp.
Trametes versicolor
•
X
X
X
X
Bz- Benzopyrene, PAHs- Polycyclic Aromatic Hydrocarbons, PEATAsTrinitrotoluene. (Source: Stamets, 2005)
Our laboratory has been involved in a series of experiment involving the use
of Pleurotus tuberregium as agent for soil remediation of crude oil polluted
46
PO
P
X
X
X
TNT
X
environment in the Delta region. Our results were very interesting (Ogbo
and Okhuoya, 2008, 2009, 2010, 2011, Oghenekaro et al., 2008, Osemwegie
et al., 2003).They include the following:

That P. tuberregium successfully grew and reduced the total petroleum in
crude oil contaminated soil.

That this mushroom was able to effectively degrade both aliphatics and
aromatics to varying degrees.

Though the fungus was not able to appreciably degrade the resins and
asphatins it was very active against them.

That a combination with other co substrates like fertilizer and agric wastes
was found to better degrade in higher terms than when alone (more for
aromatics, less for saturates and least for aliphatics).

That when sclerotia and spawn of P. tuberregium were tested for growth on
heavy metal contaminated soils, the mushroom formed mycelium in all the
substrates tested

That the mushroom had more bio-accumulative properties when grown from
spawn.

That the degree of heavy metal tolerance was different for different heavy
metals, the mushroom grew and developed fruits only on cupper
contaminated soils while it formed only mycellia on lead and zinc. This
indicated that P. tuberregium can bioaccumulate cupper more than the other
metals. This holds promise for removing heavy metals from the land by
channeling them to the fruit bodies for removal and not to be eaten (Stamets,
2005).
MUSHROOM FOR POVERTY ALLEVIATION
Mushroom collection from the wild had been in the past and still is a source of
income for rural dwellers in our communities. Therefore, mushroom production as
a commercial venture will be an effective means for poverty alleviation. This is
due essentially, to its short cropping cycle, low cost production, high profit and
quick return. These features of mushrooms can be harnessed in several ways in
47
Nigeria as is being done in other countries such as India, Kenya, Uganda and
Zimbabwe for economic empowerment of our people.
Fig. 31:Sale of mushrooms, in a rural environment
Mushroom cultivation is a big-time multimillion dollar business abroad. The report
of Okhuoya et al. (2010) succinctly indicates that the Nigerian mushrooms are still
grossly under exploited.
About two decades ago, the world production of cultivated edible mushroom was
estimated to be about 7 million tons. The combined total market value for
medicinal and edible mushroom for the same period was estimated to be in excess
of U.S. $30 billion.
In China for example, the production of mushrooms increased steadily over time
(Table 6). It is being anticipated that in the nearest future, Nigeria will be able to
have similar data for comparison.
TABLE 6: Production of Cultivated Mushrooms in China during the period1978 –
2000.
48
Year
Production
(x 1000MT)
Increase (%)
1978
60
-
1986
585
875.0
1994
2640
351.3
1997
3918
48.4
2000
6630
69.2
(Source: Chang and Miles, 2004)
In Africa, it has been reported that even if the production cost for mushroom is
doubled it would still remain more profitable than that of either maize or wheat
(Chiroro, 2005). Paradoxically, however, the production of mushrooms can even be
integrated into the already existing agro-system such as maize, wheat, etc.
MUSHROOM FUTURE IN NIGERIA
The future of mushrooms in Nigeria is still very green. Despite the number of
studies so far on mushrooms, it is important to stress that we have just scratched
the surface of the matter.
Also, the potentials in mushrooms have not been sufficiently exploited by the
industrial sector in Nigeria. It may be necessary to ask ourselves these questions:
how many mushroom growers do you have in your neighborhood? How many
mushrooms do we find in the market and how often do we get them to buy? What
can we do with the agricultural wastes around us? The questions are endless .There
are still many species in the country that are yet to be documented in literature.
49
Many are edible and medicinal. There is still so much to do in our young
mushroom industry.
Since mushrooms can have a profound positive impact on our environment and
health, it is also therefore imperative for us to commence their exploitation for
wealth creation as well as their roles in health care delivery. One can say with
much certainty that mushrooms have a lot to contribute to the economy of our dear
country.
RECOMMENDATIONS FOR THE MUSHROOM INDUSTRY IN NIGERIA
With environmental change due to climate change, deforestation, aggressive soil
erosion, many of the indigenous mushroom species are disappearing very fast. The
attention of Government is been drawn to urgently rescue our fast disappearing
species .The Government, as a matter of priority, should sponsor a national
documentation of all Nigerian Mushrooms in the six geopolitical zones.
This must be followed by having National gene banks as our heritage.
Universities actively involved in Mushroom Research like our University to be
specially funded for the establishment of Laboratories with the state of the art
equipment for the training of more Mushroom Scientists.
A National Mushroom Research Institute should be established to be cited in Benin
with the mandate to develop all mushrooms (edible, poisonous and medicinal).
Our Mushroom Biology Unit should be expanded to accommodate a mushroom
house, and an equipped laboratory with sterilization and incubation rooms, making
it a center of excellence in mushroom Research, being the first to introduce
Mushroom Science Courses in both the undergraduate and post graduate levels in
the country.
There is a very wide gap between the mushroom scientists and growers. This is
certainly not a healthy situation for the general development of the industry in the
country. For the mushroom industry to grow and assume its expected position in
the Nation’s economy, the following recommendations are suggested:
50
51
1.
There should be a meeting point for both the scientists and the growers.
Growers should attend symposia, workshops, seminars and conferences on
mushrooms.
2.
The mushroom scientist should make concerted efforts to conduct studies
that will have direct applications in the mushroom production sector.
3.
For now Research laboratories like ours in Benin should be the sole
producers of mushroom seed for growers. They should be the developers of
the best strains for the growers.
4.
It is notable from my work and the vast literature on mushroom that they are
rich in proteins and accordingly should be popularized to contribute to the
dietary needs of the people of this country.
5.
Government and the private sectors should be involved in popularizing
these crops by investing funds in research of local edible species whose
technology of production will be indigenous. Dependence on foreign
technology and exotic strains is not sustainable.
6.
Soft loans should be given to interested students with training in mushroom
science to establish small scale farms. Mushroom poisoning can only be
eliminated in our population through the commercial production of edible
mushrooms, so that people will no longer depend on mushrooms from the
wild. The market is always available for commercially produced mushrooms
and the country could even begin to earn foreign exchange from it.
7.
Mushroom growers association should be formed to bring farmers together.
Such a forum will provide new methods and new strains for cultivation.
8.
The country through Nigeria Standard Organization should begin to establish
mushroom STANDARDS for the country in collaboration with NAFDAC
and Mushroom SCIENTISTS.
CONCLUSION
My Vice Chancellor Sir, mushrooms are a major part of fungal diversity with very
unique ways of nutritional life pattern. They play major roles in the life chain by
using enzymes to breakdown complex lignin in wood and litter in the process of
natural recycling of nutrients.
They grow in all sorts of environment making them unattractive to people who
would have loved to eat the edible species. However, the lecture has shown that
they are not as horrible as they seem. They are very beneficial to man in medicine,
agriculture and in environmental cleaning. They are to be exploited so that the
nation can begin to derive the economic benefits which they offer other nations in
the West, Far East and even South Africa.
It is my belief that the lecture has made it easy for both town and gown to
understand what mushrooms are and what they do.
Thanks for listening and God Bless.
52
ACKNOWLEDGEMENTS
My thanks first and foremost go to my Lord and Saviour, the Almighty and ever
loving God who has kept me and led me to this point in my academic career. His
blessings cannot be counted for they are beyond human ability to do so. He has
remained faithful to his words in Romans 5:39 that nothing can separate us from
His love. How true that is in my life!
I am what I am today by His grace and mercy. May His name be praised for ever
and ever. PRAISE THE LORD.
I remember my father this day Mr Aroye Okhuoya of blessed memory who made
so much sacrifice to train me through to the University level. Even when men
dissuaded him not to risk allowing me accept my admission into the University for
fear that he could be stranded financially if I took up the admission. This was the
common fear then that University fees were too exorbitant for a struggling farmer
and trader. He told all who discouraged him to let him alone that he would pay the
necessary sacrifice and like the biblical Esther said if “I perish I perish”.
Thank God that he was not stranded nor did he perish by the decision to train me.
It was tough but God was faithful. By my second academic year, I got a Federal
Government award that provided my total fees including pocket maintenance
money.
I remember my late mother Madam Ajoke Okhuoya who humbly played her role as
a loving mother, supporting me with prayers; my grandmother, Madam Oraiu
Okhuoya for all her prayers and love when she was alive. My step mother Madam
Felicia Okhuoya that fed me and took care of me as her child from her womb.
53
My late Uncle Chief George Okhuoya Senior (a.k.a Olokhua) who inspired me and
encouraged me to read Science and be an expert. My late Uncles Richard
Okhuoya, Sunday Okhuoya and all my Aunties for all they did by providing me
their little while I was in School.
I thank my Cousins Barr. George Okhuoya, Chief Lugard Aikpokpo, Mr Ade
Okhuoya, Mrs Agatha Obadan (nee Okhuoya) and her husband Prof. Obadan, and
my junior siblings, Esther Aliametare (nee Okhuoya), Francis Okhuoya, Izien and
all for their prayers and support always.
My in-laws, the Duzes – Sir Festus & Lady Duze, Mr & Mrs C. Duze and the
entire family. You are all great in-laws.
Special mention must be made of my academic father and mentor Prof. D.K.G.
Ayanru who led me into the kingdom of fungi. Also Dr. Ray Harvey of blessed
Memory who supervised my PhD and tutored me in the art of mycology.
Prof. Okoloko whose teaching style inspired me into academics, Prof. F. Opute,
one of the first lecturers in M.I.T, late Prof. B. Obiamiwe who took me as his son
and bought me books.
Late Prof. J.C. Ene who was my Head of Department – Department of Biological
Sciences, Prof. E.U. Emovon, my chemistry lecturer. All pioneering staff of
Faculty of Science, Prof Laogun, Prof S. Iyahen, Prof P. Ogbuehi, Dr. Obi, Dr.
Okereke, Prof. Ahonkhai, Prof. Aluyi (BIU) and all too numerous to mention.
I thank all my class mates, some here today - Prof. Ikenebomeh, Dr. Asagba, Dr.
Okonofua, Dr. Ehigiagba, Engr. Chris Ogiewonyi, Dr. Usuoji, Mr. S. D. Owa and
many others.
Dr. Ohiorenoya my childhood Christian brother and classmate for his prayers and
support. All staff of Plant Biology- Prof. Kadiri, Prof. Idu, Prof. Aneliefo,
Dr.
Bamidele, Dr. Ejale, Dr, Dede, Dr. Ogbe, Dr. Aromose and all others.
Special mention must be made of my dear brother Engr. Jerry Asemota who
sacrificed so much of his time to draw all my graphs when I was doing my PhD in
Cardiff.
54
All my Post graduate students – late Mrs. Felicia Okogbo of blessed memory, Prof
Isikhuemen in North Carolina State University America, Dr. Efosa, Mr. Akpaja,
Abbot Oghenekaro, Theophilus Dania, Dr. (Mrs) E.M. Adongbede, Mrs Ihayere,
Dr. Ayodele, Grace Evueh and others.
I must thank my mother, Archbishop M.E. Idahosa for her prayers and
encouragement all these years, Bishop Bienose, Bishop F.E.B Idahosa and his wife,
all staff of Benson Idahosa University (B.I.U), Mama Okoje, Rev. Mrs. Oyedipe,
Dcn Mosue and members of Faith Arena Church for all their prayers and support.
Rev and Rev. Mrs. Okeke and members of Christian Brethren Ministry. All the
prayers and encouragement of Elder and Elder Mrs Ogboghodo are appreciated.
Prof. G. Omuta, Pat Donwa, Prof. S.E.N. Okoh, Late Prof. A.B.M Eborge and his
wife, Prof. Nwabuzo and his wife, Mr. and Mrs. Ogeah, Prof. and Mrs. Ofuani,
Prof. Ojogun, Prof. Oviasu and all neighbours of my friendship street for their
love and friendship.
My Christian Brothers –with whom I have shared my Christian life experience,
Rev Obadan, Prof. Iyawe, Prof. Yomi Odekunle, Omorebokhai of blessed memory,
Dr. & Dr. Mrs Obaze, Dr. Akpata, Engr. Oisamoje my best man, Rev. Humphrey
Areghan, Prof.& Mrs. A. Ogboghodo, Prof. M.S.O. Asien for being there always.
My Assistant Pastor Rev and Rev Mrs. Idu for his love and loyalty. Rev. and Mrs
Festus Akhimien, my bosom friend and family for all their love and prayers always
and staff and students of Word of Faith Group of Schools.
I must thank Prof. Emeritus A. Onokerhoraye always, in whose tenure as Vice
Chancellor, I was made Associate Professor and full Professor. The Lord bless you
Sir.
Ladies and Gentlemen, permit me to specially thank my Vice Chancellor, Prof. G.
Oshodin who surprised me on August 5 th 2010 in Senate by nominating me for the
position of Deputy Vice Chancellor of this great University without campaign. It
was a shocker to all and the appointment afforded me to serve the University in
this high office. The Lord also will surprise you with His blessings. Your darling
wife who was such a fantastic Faculty Officer when I was Dean of Faculty of
Science from 1998 to 2002.Her hard work made my work easy then. God bless you
Madam.
55
I thank all Principal Officers of the University that I have so enjoyed working with.
The Deputy Vice Chancellor, Academics- Prof. Onibere, the Registrar- Mrs.
Ogboghodo, Bursar- DR. Mrs. Nwonye, the Librarian- Dcn. Ogunrombi,
Prof. Orhue - Administrator of Ekewan Campus, Uniben Alumni, My SecretaryMrs. C. Ikpoonmwosa, Mrs. Gloria Eseiwe-Edokpolor, Miss Uwa Aghatise and my
office staff.
I thank all Old Boys and Girls of HTGS Ora, Emai Development Union and Owan
Development Association.
The Director of NIFOR (Dr. Okiy), Director of Rubber Research Institute of
Nigeria, Iyanomo (Prof. Eguaveon)
Finally, I want to thank my Darling wife who I now call mummy for being such a
great wife, as a sister and friend. You have made my life very meaningful and
fulfilling. You remain my one and only one till we see Jesus. Our four children –
Engr. Hope and his wife Bunmi, Pst. Ohioze and his wife Natasha, Mrs Isi Mba
and her husband Dr. Mba; Emmanuel and our grandchildren – Ohiomai, Ofure and
Olohirere Okhuoya.
All friends and well-wishers here present.
God bless you all.
Thanks for listening.
56
REFERENCES
Akpaja, E.O., Isikhuemhen, O.S. and Okhuoya, J.A. (2003). Ethnomycology and
usage of edible and mushrooms among the Igbo people of Nigeria.
International Journal of Medicinal Mushrooms5: 313-319.
Akpaja, E.O., Okhuoya, J.A. and Ehwerheferere, B.A. (2005). Ethnomycology
and indigenous uses of mushrooms among the Bini-speaking people of
Nigeria: a case study of Aihuobabekun Community near Benin City,
Nigeria. International Journal of Medicinal Mushrooms7: 373-374.
Alabi, R.O. (1994). Mycology and Nigerian Culture: Past, Present and Future.
Proceedings. 1st Conference of African Mycology. Mauritius, 10th-15th
June. 705p.
Ayodele, S.M. and Okhuoya, J.A. (2007a). Cultivation studies on Psathyrella
atroumbonata Pegler, a Nigerian edible mushroom on different agroindustrial wastes. International Journal of Botany, 3(4): 394-397.
Ayodele, S.M. and Okhuoya, J.A. (2007b). Effect of substrate supplementation
with wheat bran, NPK and urea on sporophore yield in Psatyrella
atroboumbonata Pegler. African Journal of Biotechnology, 6(12): 14141417.
Ayodele, S.M. and Okhuoya, J.A. (2007c). Nutritional and phytochemical
screening of Psathyrella atroumbonata Pegler, a Nigerian edible
mushroom. South African Journal of Science, 105: 158-160.
57
Ayodele, S.M. and Okhuoya, J.A. (2007d). Vegetative growth studies of
Psathyrella atroumbonata Pegler, international Journal of tropical
Agriculture and food system, 1(2):
Ayodele, S.M. and Okhuoya, J.A. (2008). Production of grain mother spawns of
Psathyrella atroumbonata Pegler. Nigerian Journal of Botany, 21(2): 396401.
Badkock, E.C. (1941). New methods for the cultivation of wood rotting fungi.
Transactions of British Mycological Society, 25: 200-205.
Buller, A.H.R (1922). Researches on fungi, vol. 2, Longman Green, London.
Buller, A.H.R. (1909). Researches on fungi, vol. 1, Longman Green, London.
Chang, S. T. (1992). Mushroom biology: a new discipline. Mycologist, 6: 64-65.
Chang, S.T. and Miles, P.G. (2004). Mushrooms: Cultivation, Nutritional Value,
Medicinal Effect, and Environmental Impact. CRC Press. Boca Raton.
451p.
Chang, S.T. and Hayes, W.A. (1978). The Biology and Cultivation of Edible
Mushrooms. Academic Press, New York.
Chiroro, C.K. (2005). Poverty alleviation by Mushroom Growing in Zimbabwe. In:
Gush R. (ed.) Mushroom Growers’ Handbook, Mushworld – Heinert
Incorporated. 298p.
Crisan and Sands, (1978). Nutritional value, In: Chang, S.T and Hayes, W.A. (eds.)
The Biology and Cultivation of Edible Mushrooms, Academic Press, New
York, pp137-168.
Dania, A.T. (2010). Ethnomycology among the Akoko-Edo people of Edo State,
Nigeria. M.Sc. Project.
De Groot, R.S. (1968). Diurnal cycles of airborne spores produced by forest fungi.
Phytopathology 58: 1223-1229.
Gregory, P.H. (1979). Speculations on basidoiospore liberation. Bulletin of the
British Mycological Society13: 120-131.
Haard, R.T. and Kramer, C.L. (1970). Periodicity of spore discharge in the
Hymenomycetes. Mycologia, 62: 1145.
58
Hammond, S.M. and Lambert, P.A. (1978). Antibiotics and antimicrobial action.
Edward Arnold Publishers, London. 63p.
Ihayere, C.A., Oghenekaro, A. O., Osemwegie, O.O. and Okhuoya, J. A. (2010).
Chemical nature of Ganodermalucidum(Curtis) Karsten from woodlands of
Edo State, Nigeria. Continental Journal of Biological Sciences, 3: 8-15.
Ikediugwu, F.E.O. and Osunde, P.U. (1977). A method for baiting Corticiumrolfsii
and of estimating the sclerotial population in the soil. Trop. Pest manage.,
23: 395-401.
Ingold, C.T. (1960). Spore Release, In:Ed. G.C. Ainsworth and A.S. Sussman
(eds).The Fungi: An Advanced Treatise, 2, Academic Press, London. pp.
679-707.
Ingold, C.T. and Cox, V.J., (1955). Periodicity of spore discharge in Daldinia.
Annals of Botany, 19: 201-209.
Ingold, C.T. (1971). Fungal Spores, Their Liberation and Disposal. Clarendon
Press, Oxford.
Ingold, R.T. and Kramer, C.L. (1965). Spore Liberation. Clarendon Press, Oxford.
Isikhuemhen, O.S. and Okhuoya, J.A. (1995). A low-cost technique for the
cultivation of Pleurotus tuberregium (Fr.) Singer in developing tropical
countries. Mushroom Growers Newsletter 4(6): 2-4.
Isikhuemhen, O.S. and Okhuoya, J.A. (1996). Cultivation of Pleurotus
tuberregium (Fr.) Singer for production of edible sclerotia on agricultural
wastes. In: Royse, D.J. (Ed.). Proceedings 2nd International Conference on
Mushroom Biology and Mushroom Products. Pennsylvania State
University, University Park.
Isikhuemhen.O.S., Okhuoya, J.A., Ogbo, E.M. and Akpaja, E.O. (1999). Effect of
substrate supplementation with nitrogen, phosphorus, potassium (NPK)
fertilizer on sporophore yield in Pleurotus tuberregium. Micologica
Neotropica Aplicada, 12: 9-21.
Jonathan, S.G. and Fasidi, I.O. (2005). Antimicrobial activities of some selected
Nigerian mushrooms. African Journal of Biomedical Research 8: 83-87.
Jonathan, S.G., Kigigha, L. and Ohima, E. (2007). Antagonistic effects of some
Nigerian higher fungi against selected pathogenic microorganism.
59
American-Eurosian Journal of Agricultural and environmental Science, 2:
363-368.
Kramer, C.L. (1982). Production, release and dispersal of basidiospores, pp 3-49,
In Decomposer Basidiomycetes – their Biology and Ecology. British
Mycological Society Symposium 4, Ed. J.C. Frankland, J.N. Hedger and
M.J. Swift. Cambridge University Press.
Munroe M. (2001). Understanding the Purpose and Power of Men. Whitaker
House, New Kensington, U.S.A. 222P.
Offidile, L.N., Uma, N.U., Kokubun, F., Grayer, R.J., Ogundipe, O.T. and
Simmonds, M.R.J. (2005). Antimicrobial colossolactones from a Nigerian
polypore Ganoderma colosum (Fr.) C.F. Baker. International Journal of
Medicinal Mushrooms,7: 437-438.
Ogbe, A., Atanodi, S.E., Akanbi, O., Babatunde, J., Edache, A., Sanusi, A., Itolo,
A.E., Atawodi, S.E. and Abdu, P. (2008). The effect of a wild mushroom
(Ganoderma lucidum) harvested from Vom, Nigerian on Elmenia tenella
infected broiler chicken. Book of Abstracts. 2nd Conference on Edible and
Medicinal Mushrooms Accra, Ghana. March, 2008. 91p.
Ogbo, E.M. and Okhuoya, J.A. (2008). Biodegradation of aliphatic, aromatic,
resinic and asphaltic fractions of crude oil contaminated soils by Pleurotus
(white rot fungi). African Journal of Biotechnology, 7: 4291-4297.
Ogbo, E.M. and Okhuoya, J.A. (2009). Effect of crude oil contamination on the
yield and chemical composition of Pleurotus tuberregium (Fr.) Singer.
African Journal of Food Science, 3(11): 323-327.
Ogbo, E.M. and Okhuoya, J.A. (2010). Bio absorption of some heavy metals by
Pleurotus tuberegium (Fr.) Sing. An edible mushroom from crude oil
polluted soil amended with fertilizers and cellulosic wastes.
InternationalJournal of Soi Science, in Press.
Ogbo, E.M. and Okhuoya, J.A. (2011). Bio availability of some heavy metals in
crude oil contaminated soil remediated with Pleurotus tuberregium (Fr.)
Singer. Asian Journal of Biological Science, in Press.
Oghenekaro, A. O., Okhuoya, J. A. and Akpaja, E.O. (2008). Growth of Pleurotus
tuberregium (Fr.) Singer on some heavy metal-supplemented substrates.
African Journal of Microbilogical Research,2:268-271.
60
Oghenekaro, A. O., Okhuoya, J. A. and Akpaja, E.O. (2009). Growth of Lentinus
squarrosulus (M.) Singer on saw dust of different tropical tree species.
African Journal of Food Science, 3(1): 7-10.
Okhuoya, J.A. (1988a). Pattern of spore discharge over Hymenial Surfaces.
Korean Journal of Mycology, 16: 57-58.
Okhuoya, J.A. (1988b). Effect of mist on spore discharge on basidiomycetes.
Transactions of Japanese Mycological society, 29: 109-113.
Okhuoya, J.A, Akpaja, E.O, Osemwegie O.O, Oghenekaro A.O, and Ihayere, C.A.
(2010). Nigerian mushrooms: Underutilized non-wood forest resources. J.
Appl. Sci.Environ. Manage. 14: 46-54.
Okhuoya, J.A. and Ajerio, F.O. (1988a). Sporocarp development of Pleurotus
tuberregium Fr. under different watering systems. Korean Journal of
Mycology, 16(4): 204-206.
Okhuoya, J.A. and Ajerio, F.O. (1988b). Analyses of sclerotium of Pleurotus
tuberregium an edible mushroom in Nigeria. Korean Journal of Mycology,
16(4): 207-209.
Okhuoya, J.A. and Akpaja, E.O. (2005). Mycomedicine and ethnomycology: the
Nigerian experience. International Journal of Medicinal Mushrooms,7:
439-440.
Okhuoya, J.A. and Etugo, J.E. (1993). Studies on the cultivation of Pleurotus
tuberregium (Fr) Sing. an edible mushroom. Bioresource Technology,
44(1): 1-3.
Okhuoya J.A. and Harvey, R. (1982a) Laboratory Cultivation of Pleurotus
ostreatus using different sawdust. 23rd Annual Conference of Science
Association of Nigeria, Benin City.
Okhuoya, J.A. and Harvey, R. (1982b). Effect of water logging on spore
production of some selected lignocolous basidiomycetes. Korean Journal
of Mycology, 14: 231-235.
Okhuoya, J.A. and Okogbo, F.O. (1990). Induction of edible sclerotia of
Pleurotus tuberregium Fr. Sing. in the laboratory. Annals of Applied
Biology,117: 295-298.
61
Okhuoya, J.A. and Okogbo, F.O. (1991). Cultivation of Pleurotus tuberregium
(Fr) Sing. on various farm wastes. Proceedings of Oklahoma Academy of
Science,71: 1-3.
Okhuoya, J.A., Eboigbe, O.E. and Isikhuemhen, O.S. (1996). Gowth interactions
between Pleurotus tuberregium (Fr.) Singer and Sclerotiumrolfsii Sacc.
FoliaMicrobiologica, 41(5): 433-435.
Okhuoya, J.A., Isikhuemhen, O.S. and Tomo, H.A. (2000). Effect of soil factors
on the growth and yield during sporophore induction from sclerotia of
Pleurotus tuberregium (Fr.) Sing. International Journal of Mushroom
Science, 3: 3-7.
Okhuoya, J.A., Isikhuemhen, O.S., and Evue, G.A. (1998). Pleurotus tuberregium
(Fr.) Sing. The sclerotia and sporophore yield during cultivation on sawdust
of different woody plants. International Journal of Mushroom Science, 2:
41-46.
Osagualekhor, D.O. and Okhuoya, J.A. (2005). Sociocultural and
ethnomycological uses of mushrooms among the Esan people of Edo State.
International Journal of Medicinal Mushrooms,7: 437-438.
Osemwegie, O.O. and Okhuoya, J.A. (2009). Diversity of macrofungi of palm
agroforests of Edo State, Nigeria. Journal of Biological Sciences, 9: 584593.
Osemwegie, O.O. and Okhuoya, J.A. and Omorusi, V.I. (2009). Ecological
diversity of macro basidiomycetes in Rubber Research Institute of Nigeria,
Iyanomo, Edo State. Nigerian Journal of Mycology,2:23-40.
Osemwegie, O.O. Isikhuemhen, O.S., Onyolu, O.J. and Okhuoya, J.A. (2002).
Cultivation of selected sporophore- only producing strain of edible and
medicinal
mushroom,
Pleurotus
tuberregium
(Fr.)
Sing.
(Agaricomycetidae) on waste paper and plantain peelings. International
Journal of Medicinal Mushroom. 4: 343-348.
Osemwegie, O.O., Okhuoya, J.A. and Evueh, G.A. (2010). Macrofungi
community of rubber plantations and lowland forest of Edo State. Journal
of AppliedSciences, 10(5): 391-398.
Osemwegie, O.O., Okhuoya, J.A., Akpaja, E.O. and Anedu, C. (2003). Water
hyacinth, an aquatic weed as a growth substrate for Pleurotus pulmunarius
62
and a ‘sporophore’ only producing strain: Pleurotus tuberregium (Pt-Omon
13). Nigerian Journal of Applied Medicinal Mushrooms. 5: 313-319.
Oso, B.A. (1975). Mushrooms in Yoruba people of Nigeria. Mycologia,67: 311319.
Oso, B.A. (1977). Mushrooms in Yoruba mythology and medicinal practices.
Economic Botany,31: 367-371.
Oso, B.A. (1981). Fungi and Mankind. University of Ibadan (Nigeria) Inaugural
Lecture. 40p.
Papazian, H.P. (1955). Sectoring varisnts in Schizophyllum. American Journal of
Botany, 42: 394-400.
Pegler. D.N. (1983). The genus Lentinus, a world monograph. Kew Bull. Add. Ser.
10. Her Majesty’s Stationary Office, London.
Rockett, T.R. and Kramer, C.L. (1974a). A technique to induce sporocarp
production and sporulation in lignicolous basidiomycetes. Mycologia, 66:
254-526.
Rockett, T.R. and Kramer, C.L. (1974b). Periodicity and total spore production by
lignicolous basidiomycetes. MycoIogia, 66: 817-829.
Scliephake, K.W., Baker, L. and Longergan, G.T. (2003). Decolourization of
Industrial Wastes and Degradation of Dye Water. In: Arora, D., Bridge, P.D.
and Bhartnagar (eds.). Fungal Biotechnology in Agriculture, Food and
Environmental Applications, Marcel Barker, New York.
Screemalu, T., (1959). The diurnal and seasonal periodicity of spores of certain
plant pathogens in the air. Transactions of the British Mycological Society,
42: 177-184.
Stamets, P. (2005). Mycelium Running: How Mushrooms Can Help Save the
World. Ten Speed Press, California. 339p.
Wainwright, M. (1989). Moulds in folk-medicine. Folklore,100: 162-166.
Walkey, D.G.A. and Harvey, C.L. (1967). Spore discharge rhythm in
prenomycetes. II. Endogenous and exogenous rhythms of spore discharge.
Transactions of the British Mycological Society, 50: 227-240.
63
Wasser, S.P. (2005). The importance Sof culinary medicinal mushrooms from
ancient times to the present. International Journal of Medicinal
Mushrooms.7: 364-364.
Zadrazil, F.(1977). The conversion of straw into feed by basidiomycetes. Eur. J.
Appl. Microbiol. Biotechnol. 4: 273-281.
Zoberi, M.H. (1964). Effect of temperature and humidity on ballistospore
discharge. Transactions of the British Mycological Society,47: 109-114.
Zoberi, M.H. (1972). Tropical Macrofungi. Macmillian, London, 159p.
Zoberi, M.H. (1973). Some edible mushrooms from Nigeria. NigeriaFields,38: 8190.
64