Biological Classification
Page No.
Topic
Biological Classification
1-4
Five Kingdom
Eubacteria
5-6
6-8
8 - 10
Motility in bacteria
10 - 22
Blue Green Algae(B.G.A)
22 - 26
Archabacteria
27 - 27
Mycoplasma
28 - 28
Kingdom Monera
Syllabus
Biological Classification
Biological Classification, Five Kingdom, Kingdom Monera,Eubacteria
Motility in bacteria, Blue Green Algae(B.G.A), Archabacteria
Mycoplasma
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Biological Classification
(1) Aristotle (382 B.C.) :- Father of biology & father of zoology.
(a)
(b)
(i)
(ii)
(iii)
2.
(A)
(B)
(C)
(D)
He classified animals into two groups :Red blood animals
Non-red blood animals
He classified plants on the basis of morphological characters in three groups
Trees
Shrubs
Herbs
Theophrastus :Time - 370 - 285 B.C.
He is known as father of ancient plant taxonomy and father of botany.
Both Theophrastus & Aristotle are Greek political philosophers.
Theophrastus wrote many books on plants. Few of them are as follows
(a) Historia plantarum (First book of botany)
(b) auses of plants
(c) Enquiry into plants
(E)
(F)
Theophrastus gave names and descriptions of 480 plants in his book Historia plantarum.
He classified plant kingdom in to four groups on the basis of growth habit-
(G)
(H)
(a) Trees
(b) Shrubs
(c) Under shrubs
It is artificial classification.
He proposed the Annual, Biennial and Perennials.
3.
Tournefort :- He proposed the concept of genus. A genus is a group of related species.
4.
John Ray :- He wrote book ‘Historia Generalis Plantarum’. He gave the concept of species.
5.
Carolus Linnaeus :- [1707 - 1778]
(A)
(B)
His real name was -Carl Von Linne
On the basis of work in latin language, he changed his name to Carolus Linnaeus. He was the swedish
scientist
He is known as father of taxonomy, father of plant taxonomy and father of animal taxonomy/binomal
system and classification science.
(C)
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(d) Herbs
Biological Classification
1
(D)
(E)
(1)
(2)
(3)
(4)
(5)
(F)
(G)
(H)
(I)
6.
(A)
(B)
(C)
Linnaeus gave the two kingdom system classification. He grouped plants and animals into kingdom
Planate and kingdom Animalia respectively.
Linneals wrote many books.
Hortus uplandicus
Philosophia botanica
Systema naturee
Genera plantarum
Species plantarum
In “Philosophia botanica” Linnaeus gave the principle of nomenclature
In “Systema naturae” Linnaeus gave the scientific names of animals. In this book he gives the detailed
description of animal kingdom.
• He also gave the outline classification of plant kingdom in this book
In “Genera plantarum” Linnaeous gave detailed description of plant kingdom.
• He classified the plant ingdom into 24 classes on the basis of stamens and carpel.
• This was an artificial classification
• The main basis of Linnaeus classification was the “Sex organs”. Therefore this classification is also
known as “Sexual classification”.
In “Species plantarum” he gave the scientific names of plants. [He gave the description of about 4000
plant species].
George Bentham (1800-1884) and Joseph Dalton Hooker (1817-1911) :Both Betham and Hooker were related to Royal botanical garden.
Scientists working in botanical garden are known as curator.
They wrote the book “Genera plantarum” (1862-1883).
In this book, Bentham and Hooker gave the biggest and natural classification of spermatophyta i.e.,
plants with seeds.
Division - Spermatophyta = 202 families
(3 classes)
Dicotyledonae
(165 familes)
Gymnospermae
(3 families)
Cycadaceae
Coniferacea
Monocotyledo
(34 families)
Gnetaceae
(3 sub classes)
Polpetalae
(Free petals)
Gamopetalae
(United petal)
Monochlamydae
(No petals)
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• In Genera plantarum, there is description of 202 families. In it, basically the description on seeded
plants is present.
Merits of Bentham and Hooker classification :• The classification of Bentham and Hooker was natural formal.
• The classification of Bentham and Hooker was mainly based on the floral characters. This waas very
appreciable because floral characters are more stable than vegetative ( root, stem, Leaves) characters.
• It is the simplest classification is based on actual observations.
Demerits of Bentham and Hooker :• In this classification the phylogeny of plants is not considered, beacuse in it, gynosperms are placed
in between dicots and monocots. The sequence of evolution is as follow :Phylogeny = Gymnosperm  Dicots Monocots
7.
A.W. Eichler :• Eichler gave the first phylogenetic classification of plant kingdom.
• The classification of Eichler is very little phylogenetic.
Plant Kingdom
Cryptogamia
Cryptos = Hidden = less
developed (Plants
wthout flower) Those
plants in which
reproductive organs are
not visible i.e, not
arranged in flower.
Sub-Kingdom
Phanerogamia
(Phaneros = visible = well
developed) (Plants with flower
like stru. Or flower) Those
plants in which reproductive
organs are arranged in flower
or flower like structure
3 divisions
2 divisions
Thallophyta
Bryophyta
Pteridophyta
Gymnosperm
Angiosperm
In this way Eichler classified plant kingdom into five divisions and arranged them in the order
of evolution (Phylogeny).
Thallophyta →Bryophyta → Pteridophyta →Gymnosperm →Angiosperm
8.
(A)
(B)
(C)
Oswald Tippo :Proposed the biggest phylogenetic classification of plant kingdom.
This classification is the complete classification of plant kingdom.
This is the most acceptable classification for books and study.
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Plant Kingdom
On the basis of embryo
Sub-Kingdom
Thallophyta = Embryo
Embryophyta = Embryo present
absent (10 Divisions)
Division
Atracheata = Bryophyta
(Non vascular plants)
9.
On the basis
of vascular
Tracheophyta
(Vascular plants)
Haeckel :- Haeckel gave three kingdom (Protista, plantae, Animalia classification) Haeckel
estabilished kingdom protista. Haeckel grouped those living organism in kingdom protista
which do not have tissue kingdom protista (prokaryotes, protozoa, porifera, algae and fungi)
10.
(A)
(B)
Karl Menz :He showed the importance of serology in taxonomy.
Similarities and dissimilarities in structure of proteins help to know the phylogenetic relationship of
living beings. Living organisms which are phylogenetically close relatives have more similarities in their
proteins
Note : Phylogenetic reletionship of plants cna be estbilished by animals serum.Serology indicates that chimpanzee is closest relative of man.
11.
(i)
(ii)
(iii)
(iv)
(v)
R.H. Whittaker (1969) :R.H. Whittaker (1969) proposed a five kingdom classification. The kingdoms defined by him were as
Monera, Protista, Fungi (Mycota), Plantae and Animalia. The main criteria used by him for making
classification are :Cell structure (Complexity of cell)
Thallus organisation (complexity of cell)
Mode of nutrition
Reproduction
Phylogenetic relationship
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*FIVE KINGDOM*
1.
2.
3.
4.
5.
Monera :All the prokaryotes (Eubacteria, Rickettsia, Actinomycetes, BGA, Archaebacteria, Mycoplasma)
Protista :All the unicelluar eukaryotes (Dinoflagellates, Diatoms, Euglenoids, Slime moulds are Protozoans
Mycota (Fungi) :Ture fungi
Planate :All the multicellular plants - Algae, Bryophyta, Pteridophyta, Gymonosperm, Angiosperm
Animalia :All the multicellular animals
Note :- In five kingdom classification virus, viroid and lichens are not mantioned.
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S.No.
1
Character
Cell type
2
Cell wall
3 Nuclear membrane
Monera
Prokaryotic
Non-cellulosic
(Polysaccharidet
amino acid)
Absent
Cellular
FIVE KINGDOM
Protista
Fungi
Eukaryotic
Eukaryotic
Plantae
Eukaryotic
Animalia
Eukaryotic
Present in some Present (without cellose) Present (cellulose)
Present
Present
Present
cellular
Multicellular/loose tissue
Tissue/organ
4
Body organisation
5
Autotrophic
(chemosynthetic
Autotrophic
Heterotrophic
Mode of nutrition &photosynthetic) (photosynthetic &
(Saprophytic/parasite)
Heterotrophic
heterotrophic)
(saprephyte/parasite)
Absent
Present
Tissue/organ,
organ system
Heterotrophic
(Holozoic/
saprophytic etc)
Autotrophic
(Photosynthetic)
THREE DOMAIN THEORY/SIX KINGDOM SYSTEM
Carl woese :- He gave three domain theory. In these domain 6 kingdoms are included. He
suggested separate kingdom for Archaebacteria.
Organism
3 D o m a in s
On the basis of sequence of r-RNA
Bacteria
Arch aea
Kingdom
Kingdom
Euk arya
Kingdom
Mon era
Arch aeba ct eria
Prot is ta My cot a Pla nta e
Animalia
*KINGDOM-MONERA*
* Bacteria are the sole members of monera kingdom
Prokaryotes :* Christensen & Dougherty gave the term ‘Prokaryota’ & “Eukaryota.
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C.B.Van Neil :Divided the living organism into prokaryotes & Eukaryotes
(1)
(A)
(B)
1.
2.
3.
Main characeterstic of prokaryotes :Cell Wall :Cell wall of prokaryotes is non cellulosis and made up of peptidoglycan (or murein) which is a
type of mucopeptide.
The structure of peptidoglycan has two parts
Sugar :- They are made up of glucose, mannose, galactose and amino sugar units.
Amino Sugar :- N-acetyl glucosamine, N-acetyl muramic acid
Amino acids :- Some amino acids are present in the wall of prokaryotes.
Other acids :Diaminopimelioc acid :- This non proteinsous amino acids is found in all eubacteria
(Gram + & Gram–) and blue green algae.
Muramic acid :- This acid is found in eubacteria and BGA
Teichoic acid :- This acid is found only in Gram (+) eubacteria.
Note :- The structure of cell wall in prokartyes is complicated and this is the primitive character. Generally the
cell wall of prokaryotes is not made up of cellouse but exceptionally there are some prokaryotes in
which cell wall is made up of cellulose, which are as follow Eg. Acetobacteria acetogenum , Acetobacter xylenum, Zymosarcina
Prokaryotes which lack cell wall :- Mycoplasma is known as joker of plant kingdom because
they show different shape and size.
2.
(A)
Cell memebrane :Like eukaryotes the cell membrane of prokaryotes is made up of lipoprotein [lipid + protein]
(B)
The space between cell wall membrane is known as periplasmic space. This space, is analogus to
lysosome because in this space the digestion of complex substance is done. In bacterial cell
membrane folded inward direction structure is called Mesosomes.
Cytoplasm :The cytoplasm of prokaryotes lacks membrane bound cell organelles.
In prokaryotic cell, the nucleus is indistinct. The nucleus of prokaryotes is also known as incipient
nucleus, genophore, nucleoid or fibrillar nucleus. Nuclear membrane is absent around nucleus. It also
lacks nucleous.
Prokaryotes aalso lack the true chromosome. Insteat of it, a false chromosome is present, which is
made up of ds circylar naked DNA + Non histone protein like polyamines. This false chromosome
coils and forms the chromosomal region, which is known as nucleoid.
In prokaryotes ribosomes are of 70s type. Ribosome are the site of protein synthesis.
3.
(A)
(B)
(C)
Examples of Prokaryotes
(1)
(2)
Eubacteria (True bacteria)
Actinomycetes
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(3)
(4)
(5)
(6)
(7)
Blue Green Algae
Archaebacteria
Rickettsia
Chlamydia
Myxobacteria
*EUBACTERIA*
History
1.
2.
3.
4.
5.
6.
They were first observed in rainy water and later in teeth scum by Leeuwenhoek (1675) and called
them “Animalcule”. This discovery was published in his book “The secrets of Nature Discovered by
Leeuwenhoek”.
F.J. Cohn and Ehrenberg first of all coined the name “Bacteria”.
Bergey placed bacteria in “Prosophyta group” and wrote a book “Manual of Determinative Microbiology”. This book is known as “Bible of bacterial classification”.
Lister developed “culture technique”. He also developed the sterilization technique” to sterilize the
surgical instruments. He is regarded as father of antiseptic surgery. He discovered the antiseptic nature
of carbolic acid. Lister first of all cultured bacteria artificially.
Louis Pasteur proposed “germ theory” and called the bacteria as “germ”. He discovered the
Pasteurisation technique”.
(Pasteuriasation technique - it is a process which means heating of drinks. It is carried out 60oC
temperature 30 minutes duration.)
Robert Koch
• Koch first obtaned pure culture of bacteria.
• He discovered the Anthrax, T.B. and cholera causing bacteria
• Koch gave some rules to prove that the bacteria are the cause of disease. These rules are known as
“Koch postulates”
• He awarded “Nobel Prize” for his work.
• Koch postulates do not applicable on obligate parasite (e.g. Mycobacterium leprae)
SIZE
1.
Smallest eubacteria
=
2.
Longest/largest eubacteria
=
3.
Largest/ longest Filamentous bacterium =
Haemophilus inf luenzae
0.2  0.3  0.5  2.0 micrometer
Epulopiscium fishelsoni
600 micrometer x 80 micrometer
Beggiatoa mirabilis
few mm.
SHAPE
Bacteria have variations in their shape. On the basis of their shape bacteria are of different types.
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1.
Coccus/Cocci These bacteria are spherical
These are smallest bacteria
Maximum resistant bacteria
eg. Diplococcus pneumoniae
2.
Bacillus/Bacilli This group includes most of the bacteria
These are rod shaped
e.g. E.coli, Bacillus anthracis
3.
Spirillum/Spirilla These are spiral shaped bacteria
e.g. Spirillum volutans, Treponema
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4.
1.
2.
3.
4.
5.
6.
1.
2.
3.
1.
(A)
(B)
(C)
Comma/vobrio Thes are comma shaped bacteria
e.g. Vibrio cholerae
MOTILITY IN BACTERIA
Bacteria are motile as well as non motile. Movement in bacteria takes place by means of
flagella. On the basis of flagella bacteria are of following types :
Atrichous - When flagella are absent , it is called atrichous form
e.g. Micrococcus, Pasteurella
Monotrichous - When only one flagellum on one end of the bacteria
e.g. Vibrio, Thiobacillus, Pseudomonas
Amphitrichous - When single flagellum is present on both the ends of bacterium.
e.g. Nitrosomonas
Lophotrichous - When a bunch of flagellum is present on both end of bacteria.
e.g. Salmonella
Cephalotrichous - When a bunch of flagella is present on one end of bacteria
e.g. Corynebacterium
Peritrichous - When flagella are found on the whole body of bacterium
e.g. Salmonella typhi
STRUCTURE OF FLAGELLA
A flagellum of bacteria is made up of three parts
Basal body
Hook
Filament
(D)
(E)
(F)
Basal body It is the basal part of flagellum and rod shaped in structure.
It lies with in cell wall and cell membrane
This proteinaceous rod shaped in structure is surrounded by two pairs of rings
(i) outer pair (ii) Inner pair
Outer pair of ring lies with in the celll wall. One ring of this pair is called L and the another caleed P.
Inner pair of ring lies with in the cell membrane . One ring of this pair is called S and the another is M.
In Gram (+) bacteria only one pair of rings (inner pair) is found
2.
(A)
(B)
(C)
Hook It connects the basal body to filament
It is the middle part of flagellum
It`s some part lies with in the cell wall
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3.
(A)
(B)
(C)
(D)
1.
2.
3.
4.
Filament It is cylindrical hollow structure made up of protein monomers
Each monomers is made up of flagellin protein. Flagellin is a contractile protein like the tubulin of
eucaryotes.
These monomers are arranged in 4 + 4 manner.
All monomers are joined with each other and so that in bacteria flagella is monofibrillar.
PILI
Bacterial cell wall is covered by numerous hair like structures called pili. Pili are smaller than flagella(pl
Pili – Sing – Pilus)
They are of two types - (A) Longer pili, (B) Shorter pili
Longer pili is also known as ‘F’ pili or sexc’ pili. Longer pili occurs in only donar (F+ or male) bacteria
and help in conjugation. These are absent in recipient bacteria or female.
The shorter pili take part in attachement.These are also known as ‘infective’ pili or fimbriae. These are
found only in pathogenic bacteria.
1.
2.
3.
Structure Every pilus is cylinderical hollo structure and composed of protein monomers.
Each monomer is made up of pilin protein. Pilin is non-contractile protein.
Pili do not play role in motility
(1)
(2)
(3)
STRUCTURE OF EUBACTERIA
Through the bacterial structure is very simple, they are very complex in behaviour.
Bacterial cell has a chemically complex cell envelope. The cell envelope consists of a tightly bound
three layered structure.
Outermost glycocalyx (may be capsule thick and tough orr slime layer-loose sheath)
Cell wall
Cell membrane
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Although each layer of the envelope performs distinct function they act together as a single protective
unit.
1.
(i)
(ii)
(A)
(B)
(c)
2.
Glycocalyx (capsule or slime layer)
Loose and thin layer is slime layer and thick and tough layer is capsule.
Capsule - Thick ,non-sticky, regular & smooth
layer
Slime layer - Thin, sticky, irregular & rough layer.
When bacteria are surrounded by capsule, called as capsulated bacteria. Formation of capsule is done
by cell membrane. Capsulated bacteria are mostly pathogenic.
Capsule is made up of polysaccharides and polypeptidexs while slime layer is made up of only
polyaccharides.
Glycocalyx protects the bacteria from W.B.C. and also help in colony formation.
Cell Wall Bacterial cell wall is made of mainly peptidoglycan or murein which is a type of muco-peptide.
In Gram(+) bacterial cell wall is single layered and thick. It is made up of peptidoglycan. Lipids are
also present but in less quantity.
While in Gram(–) bacteria cell wall is doubled layered. Inner layer is thin and composed of peptidoglycan while outer layer is thick and made up of lipopolysaccharide. Some quantity of lipoproteins and
phospholipids are also present in outer layer. Proteins (lipoprotein) present in Gram(–) bacteria are
called porins and these proteins function as channel for the entry & exit of hydrophillic low molecular
weight substances.
Difference between Gram positive and Gram negative Bacteria
1
2
3
4
5
6
7
8
G ram Positive
The bacteria remain coloured
purple with Gram staining even
after washing with alchole.
Cell wall is single layered.
Cell wall of peptidoglycan
is 20-80 nm. Thick.
G ram negative
The bacteria do not retain
do not retain the stain when
washed with alcohol
Cell wall is bilayered
Cell wall of peptidoglycan
is 8-12 nm. Thick
Wall is wavy and comes in
The wall is smooth.
contact with cell membrane
only at a few loci.
Murein (Peptidoglycan
Murein (Peptidoglycan)
content is 70-80 %
content is 10-20 %
Basal body of flagellum
Basal body of the flagellum
contains 2 rings (S & M)
has 4 rings (L,P, S & M).
Mesosomes are quite prominet. Mesosomes are less prominent
A few pathogenic bacteria
Most of the pathogenic bacteria
belong to Gram-positive group. belong to Gram-negative group.
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L-form - Bacterial cell wall can be dissoveld by Iysozyme enzyme. When bacterial cell wall is removed
artificially then bacteria are surrounded by only cell menbrane. These bacteria are called L-form
(Lister form).
Lister form - It is first developed by Klieneberger in lister laboratory London.
• Spherplast - When L-form bacteria are Gram(–) called as spheroplast.
• Protoplast - When L-form bacteria are Gram(+) called as protoplast
3.
(A)
(B)
Cell membrane This is the inner most layer
Bacterial cell mem. is made up of lipoprotein (unit membrane) like eukaryotic membrane.
4.
(A)
CytoplasmIn bacterial cytoplasm membrane bound cell organelles viz. Mitochondria, Chloroplast
E.R. Lysosome, Golgibody, Microbodies etc. are absent.
Bacterial cytoplasm shows no streming or cyclosis
(B)
Cytoplasmic organelles 1.
Mesosomes (A)
Mesosomes was discovered by F.James. The cell membrane of bacteria invaginates (extensions) in
cytoplasm at different places and form mesosomes or chondriod. These extensions are in the form of
vesicles, tubules and lamellae.
(B)
These are funtionally mitochondria like structures. Oxidative enzymes are found in mesosome. On the
basis of position and function mesosomes are of two types
(a)
Peripheral mesosome - They are situated near the cell mem. in peripheral part and their main function
is cell repiration and cell wall secretion.
(b)
Central mesosome - They are situated deep in cytoplasm and their main function is providing
help in DNA replication and cell division. These are connected with nucleoid
(a)
(b)
Functions :Their main function is cell respiration & cell wall secretion.
Help in DNA replication & cell division.
2.
Storage granules Reserve material in prokaryotic cells are stored in the cytoplasm in the form of inclusion bodies. These
are not bounded by any membrane system and lie free in the cytoplasm.
(A)
Glycogen granules - They store carbohydrate
(B)
Volutin graules - These are also known as metachromatic granules. They are made up of RNA.
They store RNA as a source of nitrogen and phosphrous.
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3.
(a)
(b)
4.
(A)
(B)
(C)
(D)
1.
(a)
(b)
2.
Photosynthetic structure Some eubactria have capacity of photosynthesis. (Purple bacteria & green sulphur bacteria no special
type of structure is found for photosynthesis.
In photosynthesis eubactria. In bactrial cytoplasm many photosynthesis pigments are scattered. The
group of pigments called chromatophres
Pigments In purple bacteria (sulphur and non sulphur bacteria chlorophyll ‘a’ and ‘b’
In green sulphur bacteria - bacteria chlorophyll ‘a’ and bacterioviridin or chlorobium chlorphyll
Chromatin material (Nucleoid)Nucleus of bactrial cell is called nucleoid or genophore or incipient nucleus or fibrillar nucleus. Nuclear
membrane and nucleous are absent.
True chromosomes are also absent in bactrial cells. Instead they contain a single chromosome. It
consists of a ds circular naked DNA (without histone), and non histone proteins. Non histone proteins
are polyamines. Nucleoid is connected to mesosomes.
Beside the main DNA another small and ds-circular DNA is also present in bacterial cell, which is
called Plasmid. It is also known as extra chromosomal or extranuclear genetic material. (The term’
plasmid)was given by Lederberg).
Plasmid have the ability to replicate independently.
Plasmids are of many types For fertility factor (F-plasmid) :- On the basis of presence or absence of ‘F’ factor, there are two
mating types of bacteria.
F+ - Cells carrying ‘F’ factors acts as donor and are called F+ or male.
F- -Cells lacking ‘F’ factor acts as recipient and are called F- or female.
When ‘F” plasmid is attached with main DNA, it is designated as episome and this type of cell is
known as Hfr cell. (The word episome was given by Jacob & Wollman)
R-Factor - Resistance to antibiotics.
STAINING OF BACTERIA
1.
2.
3.
4.
Gram Staining technique :
First of all H.C. Gram differentiated bacteria on the basis of staining.
In the first step of this method bacteria are stained with Crystal Violet and then KI solution.
After staining, bacteria are washed with Acetone or Ethyl alcohol. After washing some bacteria retain
the stain and some bacteria are decolourised.
Bacteria which retain stain (violet or purple) are called Gram(+) and bacteria which decolorise are
known as Gram(–). Gram(-) bacteria are counter stained by saffranine.
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NUTRITION IN BACTERIA
Compared to many otherr orgfanism, bacteria as a group show the most extensive metabolic diversity.
Most of thje bacteria are heterotrophic but some are autotrophic. On the basis of nutrition bactrai are
classified into following three catagories.
Autotrophs These bacteria use light or chemical energy for their own food synthesis.
(i)
(ii)
On the basis of source of energy autotrophs are following two types
Photosynthetic autotrophs • These bacteria use light energy for food synthesis.
• In these bacteria photosynthesis is non oxygenic.
• They need hydrogen ion for photosynthesis, so hydrogen ion is recevied from sources like ionrganic
sulphur compound (H2S, Thiosulphate) or organic compound (amino acids, Isopropyl alcohol Fatty
acid).
- Purple sulphur bacteria- e.g. Chromatium
- Green sulphur bacteria - e.g. Chlorobium, Thiothrix
- Purple non sulphur bactria - e.g. Rhodospirillum, Rhodopseudomonas
Chemosynthetic autotrophs • These are non photosynthetic autotrophs i.e. photosynthetic pigments are absent.
• They use chemical energy instead of light energy for food synthesis.
• Chemical energy is obtained from oxidation of chemical compound.
• These bacteria do not have photosynthetic pigments so that these bacteria oxidise chemical compounds and release energy which is used for food synthesis.
e.g. Nitryfying bacteria - They oxidise nitrogenous compounds and obtain energy.
• Nitrite bacteria - Converts ammonia into Nitrite
e.g., Nitrosomonas or Nitrococcus
• Nitrate bacteria - Convert nitrite into nitrates.
e.g. Nitrobacter
HETEROTROPHS
• Most of the bacteria are heterotrophic i.e., they can not maanufacture their own food.
• They receive their own food from dead organic matter or living organism.
These are of following types :
(i)
(a)
(b)
(ii)
Saprotrohic bacteria - These bacteria obtain food from dead and decaying organic matter.
These are of two types
Obligation saprotrophic - These bacteria obtain food only from dead organic matter. These are completely saprotrophs
e.g. Bacillus vulgaris, Clostridium botulinum
Facultative parasite - These are normally saprophytic in nature., but in the absence of dead organic
matter they can become parasitic.
e.g. Pseudomonas, Staphylococcus
Parasitic bacteria- They obtain their food from living organism
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(a)
(b)
These are of two types
Obligation parasite - They always remain parasitic.
e.g. Mycobacterium leprae
Facultative Saprotrophic - They are normally parasitic in nature but in the absence of living host, they
may become saprotrophs
e.g. Mycobacterium tuberculosis
SYMBLOTIC BACTERIA
(i)
(ii)
They form symbiotic relation with other organisms
These bacteria convert atmospheric nitrogen into nitrogenous compounds like Amino acid, NO3 or salt
s of ammonia. e.g. Rhizobium
RESPIRATION
On the basis of respiration bacteria are of two types
(A)
(B)
(1).
(2).
Aerobic bacteria
These are of two types
Obligate aerobic - These are completely aerobic and die in the absences of O2
e.g. Azotobacter
Facultative anaerobic - These are normally anarobic but also have capacity of aerobic respiration.
e.g. Fermentation bacteria except Acetobacter aceti
REPRODUCTION
Bacteria reproduce by two methods
Asexual reproduction
Genetic recombination
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(1).
(i)
Asexual fission Binary fission (a) This is the most common method of bacterial reproduction. Binary fission takes place by amitosis.
(Amitosis is characteristic of procaryotes. Mitosis and meiosis never occur in prokaryotes).
(b) First of all DNA replication takes place in bacterial cell. Under favourable conditions bacterial cell
divides as into two cells due to formation of transverse septrum in the centre of the cell. Each daughter
cell grows into a new bacterium.
(c) Under favourableconditions, the cells of bacteria divides after every 20 minutes.
(ii)
By Endospore - Endospore formation occurs under unfavourable conditions.
(a) It is a highly resistant structure. It is resistant to high temp., radiations antibiotics and chemicals.
(b) It is also known as “reproduction with out multiplication”.
(c) Endospore is highly resistant structure due to presence of Ca-dipicolinate in cortex.
(d) Endospore is stained by Nigrosin reagent.
(e) Endospore formation is seen in mostly bacillus type bacteria.
(2)
Genetic recombination
True sexual reproduction is absent in bacterial because it does not involve fusion of male and female
gametes to produce a diploid zygote. Genetic recombination involves transfer of some genes from a
bacterium to another bacterium. There are many methods of genetic recombination.
Transformation(a) In this process one kind of bacterium is transformed into another kind.
(b) Transformation was first of all discovered by Griffith(1928) in Diplococcus pneumoniae.
(c) Detailed study was carried out by Avery, Macleod and Mc Carty
(1)
Griffith`s experiment :
S - IIIstrain - This strain was pathogenic
R - II strain - This strain was non pathogenic
(a) First of all R- II was injected to a Mice - Mice survived and did not show symptoms of pneumonia
(b) S- III injected to a mice - Mice developed symptoms of pneumonia and died.
(c) S- III strain heat killed and then injected in mice - Mice did not develop the pneumonia.
(d) Heat killed S - III were incubated with the living R-II for some time. This mixture was then injected
in to mice - Mice developed pneumonia and died.
Conclusion On the basis of this experiment Griffith concluded that some materail of S- III strain transformed the
R-II into S-III. But Griffithcould not indentify the material responsible for transformation. It was later
indentified by Avery, Macleod and Mc Carty as DNA.
(2)
Conjugation
Conjugation was first discovered in 1946 by Lederberg and Tatum in E.coli,. They were awarded
Nobel prize for their work.
Conjugtion between F+ and F(a) First of all cell (F+) is attached to recipient cell (F- ) with the help of sex pili. Sex pili function as
conjugation tube.
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(b) The ‘F’ factor (F-plasmid) now replicates and the replica moves to F- through conjugation tube.
(c) Both the cells are then separated. Due to transfer of ‘F’ factor F- bacteria now becomes F+
bacteria .
(3)
Tranduction
When gene transfer process between two bacteria carried out by virus (bacterio phage) called transduction.
ECONOMIC IMPORTANCE OF
BACTERIA
HARMFUL ACTIVITIES
1.
Disease in Human beings :
Disease
Tuberculosis (T.B.)
Leprosy
-
Diphtheria
Tetanus
Typhoid
Plague
Pneumonia
Jaundice
Pertissis
Meningitis
Gonorrhoea
Cholera
Dysentery
Syphilis
-
Bacterium
Mycobacterium tuberculosis
Mycobacterium leprae
Corynebacterium diphtheriae
Clostridium tetani
Salmonella typhi
Pasteurella pestis or Yersinia pestis
Diplococcus pneumoniae
Leptospira ictero
Bordetella pertussis
Neisseria meningitidis
Neisseria gonorrhoeae
Vibrio cholerae
Shigella dysenteriae
Treponema pallidum
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2.
Disease in Animals :
Anthrax
Black leg
3.
-
Disease in Plants :
Citrus canker
Leaf streak of rice
Angular leaf spot of cotton
Crown gall in many plants
Fire blight of stone friut
(apple and peas)
Brown rot or wilt of potatoes
Black leg and soft rot of potatoes
Bacterial leaf blight of rice
Bacillus anthracis
Clostridium chanvei
Xanthomonas citri
Xanthomonas oryzicola
Xanthomonas malvacearum
Agrobacterium tumefaciens
-
Erwinia amylovora
Pseudomonas solanacearum
Erwinia caratovora atroseptica
Xanthomonas oryzae
4.
Denitrification - Denitrifying bacteria Some bacteria convert soil nitrates into nitriteis and then nitrogen. These bacteria reduce the fertility of
soil.
e.g. Thiobacillum denitrificanes, Psedumonas denitrificans
5.
Food poisoning Some bacteria are responsible for poisoning. These are of three types Salmonella enteridis - These bacteria survive on milk products and also in intestine of man. They
secrete toxins.
Symptoms - Vomiting, Dysentery
Staphyloccouc aureus - Thse bacteria survive on milk and egg products. They secrete toxins which
damage the central nervous system. These toxins are heat resistant.
Botulism- Clostridium botulinum - It is most lethal type of food poisoning. These bacteria survive in
absence of O2 . These bacteria grow in canned food. Their toxins damage the parasympathetic
nervous system. It leads to paralysis of both smooth and striped muscles, resulting in immediate
death.
Water pollution Several bacterial forms cause water pollution. These bacteria spoil the water.
e.g. Vibrio cholera, Salmonella typhi, Shigella dysenteriae.
(A)
(B)
(C)
6.
7.
1.
Biological Weapons Some bacteria are used as bio weapons such as Anthrax causing, Botulism, Cholera causing bacteria.
USEFUL ACTIVITIES
Bacteria are important Decomposers (a) Ammonification- Ammonifying bacteria Some bacteria convert Protein (present in decaying plants & animals) into Ammonia.
e.g. Bacillus vulgaris, Bacillus mycoides, Bacillus ramosus
(b) Dead organic matter -
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2. Inorganic compound
Decomposing
bacteria
1. Dead organic matter
3. Salt of N, P, Fe,
S present in soil
n ut ri rie n t
5. Death
Ca rni v ore s
2.
Nitrification - Nitrifying bacteria These bacteria convert Ammonia in to Nitrite and later into Nitrate.
NH3
3.
(A)
(B)
H erb iv or es
4. Absorption
by plants
Nitr oso m on as
NO2 (Nitrite) N itr ob ac t er
NO3 (Nitrate)
Nitrogen fixation - Nitrogen fixing bacteria These bacteria convert the atmospheric nitrogen into nitrogenous into compounds like amino acids,
nitrate or ammonium salts.
Nitrogen fixation is done by two methods Symbiotically - Some bacteria live symbiotically and do nitrogen fixation.
e.g. Rhizobium - In the root nodules of legumes such as alfalfa, sweet clover, swet pea, lentils, garden
pea, broad bean, clover beans.
Aerohizobium - In the stem nodules of sesbania
Azospirillum - Found on root surface of cereals i.e., superficial symbiosis (e.g. Wheat, Rice, Maize).
Frankia (Filamentous bacteria) - In root nodules of non leguminous plant Casurina and Alnus plants.
Asymbiotically - Some bacteria occurs free in soil and do nitrogen fixation.
e.g. Clostridium, Chromatium, Azotobacter, Azospirillum, Beijernickia
Rhodomicroblum, Rhodospirillum, Rhodopseudomonas
Note :- Azotobacter and Beijernickia are aerobic Rhodospirillum is anaerobic bacteria. Both Rhizobium and
Frankia are free living in soil, but as symbionts, can fix atmospheric nitrogen.
4.
Dairy products Dairy products are formed with help of bacterial fermentation
Curd - It is made by milk
Milk
Streptococcous lactis or
Lactobacillus lactis
Curd
Note : Lactobacillus lactis (LAB/Lactis acid bacteria) increase vitamins B12 in curd LAB also help in checking
the disease causing microbes in stomach.
5.
Antibiotics • Term antibiotic was given by S.A Waksman
• First discovered antibiotic was Penicillin it was obtained from fungi Penicillium
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
1.
2.
3.
4.
5.
6.
7.
8.
9.
• First discovered antibiotic from bacteria was streptomycin.
• Many antibiotic medicines are obtained from bacteria.
• Some substances produced by microorganism which ihhibit the growth of other micro-organism are
called antibiotic substance.
• These antibiotic medicine cure the disease through the competitive inhibition.
Bacteria
Antibiotics
Bacillus licheniformis
Bacitracin
Bacillus polymyxa
Polmyxin
Bacillus brevis
Gramicidin
Bacillus subtilis
Subtilin & Bacitracin
Streptomyces griseus
Streptomycin
Streptomyces venezuelae
Chloromycentin (chloramphenicol)
Streptomyces aureofaciens
Aureomycin (Chlorotetracycline) & tetracyline
Streptomyces rimosus
Terramycin (oxytetracycline)
Streptomyces fradiae
Neomycin
6.
Industries Many bacteria are used in industries
(A)
Alcohols formation :Ethanol is formed with the help of yeast (fungi) or bacteria (Sarcina ve• utriculi) by the process of fermentation.
C6H12O6 Sarcina veutricul i

(B)
Alcohol (Ethanol)
Vinegar formation (Acetic acid)
Ethanol Acetobact er aceti
Acetic acid
(C)
Retting of fibers e.g. Clostridium Butyric acid bacteria
(D)
Flavouring of tea and tobacco leavese.g. Bacillus megatherium, Micrococcous condiscence
(E)
Cleaning of hides e.g. Any saprotrophic
(F)
Production of Vitamins Riboflavin (Vit. B2)
• Clostridium butylicum produces
• Propionibacterium and Bacillus megatherium produce - Vit. B12
• E.coli produce
Vit. E, Vit. K. (E.coli bacteria found in alimentry canal of human
beings)
7.
Decomposing bacteria - Some bacteria decompose the harmful chemicals.
• Flavobacterium -2, 4 - D
Particle decomposition in long term duration
• Acetobacter
DDT
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8.
Bacteria for specific pests - Bacteria are use to kill specific pests
e.g. Bacillus popollinae - Japaneese Beetle
Bacillus sphaericus - Anopheles
9.
Purity of ganga water - In gangatic water a bacteria Bdellovibrio bacterovorus is found, they kill the
other water polluting bacteria.
10.
Pollution indicating bacteria Water in which E.coli bacteria are present known as polluted water. Quality of water depends on
number of E.coli. If E.coli are very much in no. the water will be highly polluted. So the E.coli is known
as pollution indicating bacteria.
11.
Oil Clearing bacteria e.g. Pseudomonas putida
12.
Bacteria for genetic engineering -e.g. E.coli
and Agrobacterium
*SOME IMPORTANT POINTS
(1)
(2)
Mycolic acid
Bacteroids
(3)
Pus bacteria
• Staphylococcus (produce yellow pus)
• Pseudomonas (produce blue pus)
nif gene - “Nitrogenase Inducing factor” • nif gene is present in all nitrogen fixing bacteria
Bacillus thuringiensis - This bacterium is releated with “Bt” toxin.
(4)
(5)
(A)
(B)
(C)
(D)
-
Present in all filamentous bacteria
Symbiotic bacteria which are present in root nodules of plants are known as
bacteroids e.g. Rhizobium
* BLUE GREEN ALGAE (B.G.A)*
According to two kingdom system B.G.A were included in class Cyanophyceas or Myxophyceae
of Algae. But now they are included in Kingdom Monera, because of their prokaryotic nature.
B.G.A is now known as cyanobacteria. The name cynobacteria was suggested by ICNB
(Internationalcode of Nomenclature for Bacteria) in 1978.
Cyanobacteria are photosynthetic prokaryotes. Some eubacteria also have photosynthesis process
but there is some difference in the photosynthesis of cyanobacteria and eubacteria.
Cyanobacteria were the first organism that produced O2 on our earth.
They have following pigments.
• Chlrophyll ‘a’- green
• Carotenoids - yellow
• C- Phycocyanin - blue
• C- Phycoerythrin -red
Note : Cyanobacteria are not always of blue-green colour. eg. Trichodesmium is a red coloured. The red
colour of water of red sea is due to this alga.
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Eubacteria
Cyanobacteria
In
them
photosynthesis
In them photosynthesis
non-oxygenic i.e. O 2 is not
is non-oxygenic i.e. O 2 is not
involved during photosynthesis involved during photosynthesis
They have following pigments They have following pigments
* Bacteriochlorophyll 'a' and
* Chl. 'a'- green
'b' (in purple bacteria)
* carotenoids - yellow
* Bacterioviridin (in green
* C - Phyocolyanin - Blue
bacteria)
* C - Phyloerythrin - Red
Different forms of BGA or Cyanobacteria :
(A)
Unicelluar : Some B.G.A. are unicellular
e.g. Spirulina
Note : Spirulina is an edible B.G.A. because it has very large amount of proteins. It can be grown artificially in
water tanks. It is used as a fodder for cattle.
(B)
Colonial - Some B.G.A. are found in colony i.e. cell colonies.
e.g. Anabaena, Microcystis
(C)
Filamentous - Some B.G.A. are filamentous. Their are many cells arranged in a row in their body. The
filament of B.G.A. is known as trichrome.
e.g. Oscillatoria
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*Structure of B.G.A.*
(A)
The structure of B.G.A. is similar to Gram(-ve) eubacteria.
(B)
B.G.A. is surrounded by a mucilagenous sheath. This sheath is made up of mucopolysaccarides
[Pectic acid]. The cell wall of B.G.A. is also bilayered. Outer wall is made up of lipopolysaccharides
and the inner wall is made up of pepetidoglycan.
(C)
The cell membrane of B.G.A is alo made up of lipoproteins like that of eubacteria.
The cytoplasm of B.G.A. is divided into two parts
(a)
(b)
Peripheral cytoplasm It is known as chromoplasm. In this part gas vacuoles and photosynthetic thylakoids are found. Photosynthetic pigments are present on the surface of these thykoids.
Central cytoplasm This is known as centroplasm. In this region nucleoid is present. Ribosomes are of 70s type, and are
scattered in both chromoplasm and centroplasm.
*Note :
(1)
the cytoplasm of prokaryotes lack membrane bound cell organelles but exceptionally in B.G.A. two
membrane bound structure are present.
(i) Gas vacuole - It provides the buoyancy to the B.G. algae in water.
(ii) Thylakoids or Chromatophores - Photosynthetic pigments are present on its surface.
(2)
Exceptionally gas vacuoles are also present in purple and green photosynthetic bacteria.
Stored food B.G.A. stored its food in the form of  granules and  -granules.
•  granules - They are made up of cyanophycean starch. It is structurally similar to glycogen.
•  -granules - They are made up of fat droplets.
Oscillatoria can survive in hot water springs.The temperature of this water is about 80o C. Oscillatoria
have capacity to tolerate high temperature because of Homopolar bonds in proteins - Proteins are denatured at high temperature and the living beings die.
But homopolar bonds are present in the proteins of cytoplasm of Oscillatoria, which can not break
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(A)
(B)
easily and the bonds are very much in number so they can tolerate high temperature.
Nitrogen fixation Some of the B.G.A ., can perform Nitrogen fixation. They converts atmospheric nitrogen in to nitrogenous sompounds like amino acids, nitrates. These nitrates increases the fertility of soil. Hence B.G.A.
improves the fertility of soil by nitrogen fixation.
B.G.A. fix of soil by nitrogen fix in two forms Symbiotic form and Asymbiotic or free living form
Symbiotic form
Free living form
e.g. Anabaena & Nostoc
e.g. Anabaena, Nostoc & Aulosira
These B.G.A. form symbiotic
Some B.G.A. are found free living
association with many plants
in water and soil and perform nitrogen fixation.
and performs nitrogen fixation.
Aulosira This B.G.A. is found in plenty in paddy fields.
for e.g.
Its germinates in water. This B.G.A. performs
In thallus of Anthoceros
nitrogen fixation due to which the production of rice
In the leaves of Azolla
is increases.
In the coralloid roots of Cycas
Oscillatoria = also fix N2 in paddy fields.
In root nodules of Trifolium
Azolla - If Azolla is grownwith rice, then
production increases up to 50%
[because Anabaena are found in the
leaves of Azolla]
1.
2.
3.
IMPORTANT POINTS
A special type of cell is found for nitrogen fixation in BGA which is known as heterocyst. Heterocysts
is thick walled, non green cell.
Heterocyst don`t perform the photosynthesis like other vegetative cells.
Nitrogenase enzyme is necessary for nitrogen fixation. For the synthesis of this enzyme, their is a
special type of gene present in BGA, which is known as nif-gene [nif = nitrogenase inducing factor].
This gene stimulates the production of nitrogenase enzyme.
REPRODUCTION In BGA reproduction is done by two main processes
(1) Vegetative
(2) Asexual
(1)
(i)
(ii)
Vegetative Reproduction Binary fission This is the most common method of reproduction in prokaryotes. By this process only unicellur prokaryotes can reproduce.
e.g. Spirulina
Fragmentation Filamentous prokaryotes, reproduce by this process. At the time of reproduction, some cells becomes
thickwalled, which are known as harmocyst (hormogonia). Due to the formation of homogania, the
filament get broken and each part is grown into a new filament
e.g. Oscillatoria
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(2)
Asexual Reproduction It is method of protection from unfavourable conditions
e.g. Akinete formation in Nostoc.
Note : In B.G.A. genetic recombination was first discovered by H.D kumar
WATER BLOOM “Excessive growth of plants in water, that pollute the water”
(A)
It mainly develops due to BGA
e.g. Anabaena flos-aquae, Microcystic aeruginosa, Aphanizomenon flo-aquae
(B)
BGA grow rapidily in water and secrete toxic substance are known as death factor. Death factor
is the main cause of death in aquatic animals. It also gives toxicity and bad odour to the water.
ECONOMIC IMPORTANT OF BGA
(1)
(2)
(3)
(4)
(5)
(1)
(2)
Useful activites :
They provide fertility to soil by nitrogen fixation.
e.g. Nostoc, Anabaena, Aulosira, Oscillatoria
The most proteinsaceous food for animals
e.g. Spirulina
It gives fertility to sterile alkaline soil and usarsoil.BGA secretes an acidic chemical which decrease the
alkalinity of soil
e.g. Nostoc comune, Scytonena ocellatum, Aulosira fertilissima
Some BGA are used as green manure
e.g. Anabaena, Spirulina
Some BGA secrete toxin, which inhibits the growth of mosquito larva in water
e.g. Oscillatoria Anabaena, Aulosira
Harmful activites Wate bloom
BGA that grow in water tanks, pollute the water
e.g Oscillatoria
SOME IMPORTANT POINTS
• Cyanoacteria are Gram(-ve) oxygenic photosynthesizing organisms. It is belived that origin of O
2
on earth was due to cyanobacteria.
• Maximum cyanobacteria are non motile but some filamentous cyanobacteria show gliding and oscillatory movement.
e.g. Oscillatoria
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*ARCHAEBACTERIA*
“Group of ancient bacteria’
1.
2.
3.
4.
5.
6.
1.
(i)
(ii)
(iii)
2.
3.
(A)
(B)
(C)
(D)
(E)
(F)
Evolutionary they are primitive. they were the first to be born on our planet and they are present
nowdays with their primitive characters. They are the “Oldest living fossils”.
They are different from eubacteria in many ways.
Mostly archaebacteria are obligate anaerobes.
Thermococcus, Methanococcus and Methenobacteria exemplify archaebacteria that contain
protein homologus to eukaryotic core histones.
Their cell wall is not made up of peptidoglycan like that of eubacteria. Their cell wall is made up of
complex polysaccharides and complex polypeptide.
Their cell membrane is not a unit membrane, while in eubacteria the cell membrane is unit membrane.
Cell membrane of archaebacteria is highly complex. Cell membrane in archaebacteria is single layer of
branched chain molecules of lipids while the lipid present in cell membrane of eubacteria are straight
chainmolecules. Due to branched chain structure, archaebacteria have more resistance ability as compare to eubacteria are not effected by temp., high salinaity, radiations and change in PH. They are
resistant to all these.
Methanogens “Methane producting bacteria”
These bacteria convert CO2 of swampy areas (Marshy) into methane (CH4)
e.g. Methanobacterium, Methanococcus, Methanomicrobium
These bacteria convert the organic substance (cellulose) present in cow during into methane by
fementation (Gobar gas fermenter).
e.g. Methanobactrium, Methanococcus, Methanomicrobium
An archaebacterium is found in the rumen of cattle, where it digests the cellulose by fermentation and
convert it into methane.
e.g. Rumenococcus.
Halophiles These archaebactria are found in extreme salty areas.
Halophiles are surrounded by purple menbrane in which a pigment, bacteriorhodopsin is found due to
this reason membrane absorbed the bright light and directly froms ATP i.e. They cannot prepare food
(carbohydrates) like eybacteria. Instead of it they directly from ATP. Therefore Halophiles are non
photosynthetic.
Thermo acidophiles These archaebacteria are found at those places where temperature is approx 80o C and medium is
acidec [pH =2]
They are found in hot sulphur springs. These can also survive at 100 o C temperature.
Hot water sulphur springs are found in the Himalyan region.
They oxides sulphur to H2SO4 and obtain energy. This is used to prepare food. Due to conversion of
sulphur to H2SO4 the medium (water) become acidic in nature.
They are example of chemosynthetic bacteria.
Exceptionally these archaebacteria are facultative anaerobic.
e.g. sulpholobus
Note : Barophilic prokaryotes - Prokaryotes which grow and multiply in very deep marine sediments.
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*MYCOPLASMA*
• In 1889, two French scientists E.Nocard and R. Roux while studying pleural fluids of cattle suffering
from pleuropneumonia disease, discovered the organisms which are known as mycoplasma and were
designated as PPLO (i.e. Pleuropneumonia like organism).
• Nowak (1929) put these organism under the genus Mycoplasma.
• The Japaneese Doi et. al (1967) first discovered that the “Aster yellow” diseases of plants are
caused by Mycoplasma. Doiet. al. named thses pleomorphic organisms as mycoplasma like organisms
(MLO). According to Doi, phloem cells (Sieve tube & phloem parenchyma) of plants are much affected by this disease.
4.
5.
6.
7.
8.
9.
MAINS POINTS :Mycoplasma unicellular, smallest prokaryotic organsims. This diameter of cell varies from 0.1  m to
0.3  m .
Cell membrane is tri-layered and made up of lipoprotein. Both DNA (ds DNA circular mainly) and
RNA (ssRNA) are present.
Mycoplasma may be the simplest form of life capable of independent growth, reproduction and metabolism.
They are cell wall hence, they exhibit pleorphism and thus called as “Joker of plant kingdom”.
Osmotrophic mode of nutrition (absorption of nutrients by osmosis) is found in Mycoplasma.
They are resistant to antibiotics as penicillint that act on cell wall.
They are sensitive to teracyclin & chlormaphenicol that act on metabolic activities.
Most of the species of Mycoplasma are facultative anaerobs.
Species of Mycoplasma are saprophyte or facultative parasite.
1.
2.
REPRODUCTION IN MYCOPLASMA
Binary fission : Most common method of reproduction in Mycoplasma.
By primary structures or “Elementary bodies”
(i)
(ii)
(iii)
(iv)
(v)
Plant disease
Little leaf disease of Brinjal
Bunchy top of papaya
Witches broom of Ground nut (Legumei)/Potato.
Aster yellow disease of sunflower.
Sttubborn disease in citrus
(i)
(ii)
(iii)
Animal disease
M.hominis causes male sterility/Genetals inflammation in human
Mycoplasma mycoides causes bovine pleuropneumnoia.
Mycoplasma pneummiae causes primary atypical pneumonia.
1.
2.
3.
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