Arthrospira Platensis: Brief History and Description
Mark Barnett
Biology 221, University of Missouri – Rolla
Abstract: Society has come to associate microbes with dreadful diseases, undesirable outcasts
of the domain of life. Chemicals have been devised to eradicate them, derogatory terms such as
“germs” have been used to debase and propagandize against them. However, increasingly,
society is recognizing the benefits of microbes, in terms of selective degradation of waste
products, useful syntheses of complex compounds, especially those intended for pharmaceutical
applications, and food. Arthrospira platensis is one bacterial organism, which in a twist of irony,
is preyed upon by humans. And so our story unfolds…
January 21, 2007
Introduction:
Known commonly as
Spirulina, blue-green cyanobacteria, A.
platensis has been harvested for food
purposes since ancient times. It was first
described in 1940, by Dangeard, a French
phycologist, who received a sample from a
French pharmacologist colleague, Creach,
embedded with the French Army in
equatorial Africa, near present-day Chad.1
Creach found little biscuits of the dried
bacterial matter, known locally as Dihe,
being sold in the local market place.1,2 Dihe
was the hardened product of A. platensis,
which was collected from mats floating on
small lakes or ponds, dried, and broken into
pieces for sale. However, the report went
unnoticed and 25 years would pass before A.
platensis was rediscovered by the Belgian
botanist, J. Leonard.1
Interestingly,
the
Spanish
conquistadors found a similar species, A.
maximus, harvested from Lake Texcoco near
present-day Mexico.1 The blue-green ooze
was collected with fine fishing nets and
incorporated into bread. The local word was
tecuitlatl, which translates into “stone’s
excrement.” These two instances represent
the only recorded observations in which
humans used microbial biomass for food
consumption.
Biology:
A. platensis is a blue-green
photolithoautotroph, meaning it derives its
energy from sunlight and uses carbon
dioxide as its carbon source.2 Minerals are
derived from the inorganic sources in the
environment. As with other cyanobacteria,
A. platensis is gram (-), exhibiting cell
membrane, cell wall and outer membrane.
A. platensis thrives in shallow alkaline
ponds and lakes, where the pH is in the
range of 9 to 11, and the salt concentration
very high, on the order of 30 g/L. Such an
environment is inhospitable to most other
organisms and as such, A. platensis may find
itself the only organism of any significance.1
The alkaline salts are typically sodium
carbonate and bicarbonate which are
components of volcanic ash. In terms of
photosynthesis, A. platensis is prodigious in
its production of oxygen. Rates of 1.2 – 2.4
g O2/m2/hr have been reported.1
The distinguishing feature of A.
platensis is its helical shape. Individual
cells multiply in the usual manner via cell
fission. The superstructure is the helical
multicellular trichome. When the trichome
is mature, it breaks up into short cellular
chains of 2 – 4 cells, or hormogonia.1,2
These glide away and begin new trichomes.
Ecology and Food: A. platensis is rich in
easily digested protein and phytochemicals.3
The protein is considered a complete protein
since it contains all the essential amino
acids. With around 65% protein (dry mass)
A. platensis is superior to all plant sources of
proteins, although perhaps not the quality of
meat.
The environmental and economic
benefits of growing A. platensis can readily
be illustrated when compared to primary
agricultural crops. This cyanobacteria can
be obtained in high yields and has minimal
growth requirements. Pound for pound of
protein, it takes 30 times more water to raise
beef than to grow A. platensis, and roughly 8
times more for corn, soybeans and eggs.4,5
Shear volume is not the only consideration.
Beef requires fresh water, whereas A.
platensis may be grown using brackish and
recycled water.
The geographic space
comparison is also striking. In terms of
pounds of protein produced per acre, A.
platensis is 100 times more productive than
beef and more than 10 times more
productive than corn or soybeans.
In
addition, A. platensis can be cultivated on
infertile land, while the other agricultural
crops have more stringent requirements.
Another advantage for the cyanobacteria, A.
platensis can be easily harvested, filtered
and washed. Disadvantages for traditional
agricultural crops include erosion, and the
toxic environmental affects of pesticides and
herbicides. A. platensis does not contribute
to these issues.
Medicine: Rich in protein, vitamins and
other important phytochemistry, A. platensis
has been recently gaining the attention of
medical researchers. Studies are showing
that A. platensis may exhibit antiviral,
anticancer,
antimicrobial,
and
anti6
It has also been
inflammatory activity.
shown to have beneficial effects on
controlling cholesterol, diabetes, coronary
artery disease, weight loss, and wound
healing.
Conclusion: Could this ancient prokaryote
hold the cures for our modern ailments?
Could this little cyanobacteria help feed a
hungry world as arable land and fresh water
become more scarce? Microbiology is
beginning to elucidate the benefits of A.
platensis and as scientists learn more, it is
likely this bright, blue-green bacteria will
become increasingly important as a food and
health supplement.
References:
[1] Ciferri, O., Microbiological Reviews,
1983, 47 (4), 551-578.
[2] Perry, J.; Staley, J.; Lory, S.; Microbial
Life, Sinauer Associates, Inc., 2002, p 768.
[3] Wikipedia,
http://en.wikipedia.org/wiki/Spirulina_%28d
ietary_supplement%29
[4] Moorhead K., Morgan, H., Spirulina:
Nature’s Superfood, Nutrix, Inc. (1995).
[5] Spirulina.Com,
http://www.spirulina.com/
[6] Kahn, Z., Bhadouria, P., Bisen, P.,
Current Pharmaceutical Biotechnology,
2005, 6, 373-379.
Arthrospira (Spirulina) Platensis
Mark Barnett
January 18, 2007
Ode to a Microbe
Microbe, microbe, spiraled your body be,
Green-blue in color, tropical water lover,
Thriving in conditions of alkalinity [1].
Stone’s excrement by Aztecs [1,2], in Africa, Dihe [1-3],
From domain Bacteria to genus Arthrospira,
Nutritious, proteinaceous, rich in phytochemistry.
Undemanding, environmentally sound,
Oxygen producer, CO2 reducer,
Energy efficient, water conserving, no loss of ground [4].
“Super food,” says WHO; considered excellent by NASA [2,4],
Whether desert locations or outer space stations,
Count on this filamentous helical cyanobacteria.
Research is just beginning; there is much more to explore.
Anti-viral, anti-cancer, memory, immunity enhancer,
Food supplement, pharmaceutical, health and wellness galore [5]!
- Mark Barnett, January 18, 2007
References:
[1] Ciferri, O., Microbiological Reviews, 1983, 47 (4), 551-578.
[2] Wikipedia, http://en.wikipedia.org/wiki/Spirulina_%28dietary_supplement%29
[3] Perry, J.; Staley, J.; Lory, S.; Microbial Life, Sinauer Associates, Inc., 2002, p 768.
[4] Spirulina.Com, http://www.spirulina.com/
[5] Kahn, Z., Bhadouria, P., Bisen, P., Current Pharmaceutical Biotechnology, 2005, 6, 373-379.
Arthrospira platensis
Across
1. Corkscrew shape, same as that of DNA.
4. Research shows that A. platensis has properties that kill
viruses.
5. Aztec name means excrement from this inanimate object.
6. Basic aqueous environment.
7. World Health Organization (WHO) name for A. platensis.
Down
2. Phylum to which A. platensis belongs.
3. Color of A. platensis.
7. Curved shape similar to 1 across, but not the same.
8. Beneficial gas for humans.
9. African word for bisquits or cakes cut from A. platensis mats.