Question

A) What is the natural habitat of Spirulina (cyanobacteria)?

B) How does Spirulina (cyanobacteria) acquire nutrients and transform energy?

C) What is the type of movement of Spirulina (cyanobacteria)?

D) What is the ecological role (niche) of Spirulina (cyanobacteria)?

E) Name a unique structural feature of Spirulina (cyanobcateria).

Answer 1

A) Spirulina/cyanobacteria is a genus of blue-green algae which is normally used as food supplement. They are mostly found in aquatic environment. More specifically in the alkaline (pH 8.5), saline and brackish water as well as fresh water which recieve direct sunlight, mostly in subtropical and tropical regions of the world (mesophilic, temperature 30-40deg Celsius).

B) Cyanobacteria's are autotrophic, i.e., they synthesize their own food by photosynthesis in an orgaelle called thylakoid. They harbour a blue-green pigment called phycocyanin which is instrumental in capturing sunlight to produce their own food. Additionally, they also contain chlorophyll a and carotenoids. They use inorganic carbon mainly bicarbonate as the source of carbon and acquire it by a carbon concetrating mechanism in their aquatic environment. All these accumulate in certain small compartement within th bacteria called carboxysomes.

C) Spirullina are motile organism and harbour coiled filaments and trichome for this purpose. These trichome are mostly cylindrical and can be pointed or blunt, loose or tight and of various different lengths and mostly show gliding motility.

D) Spirulina or cyanobacteria play a very important role of fixing nitrogen in the environment under anaerobic condition. Through this they provide nitrogen source to the plant for biosyntheis of proteins and nucleic acids via symbiotic relationship. Apart from this some bluegreen algae also forms lichens.

E) Spirulina harobur protein gas vesicles which provides them with bouyancy in the aqueous environment. Also, some spirulina which can fix nitrogen form a specialized streucture called the heterocyst which helps in nitrogen fixation. They also harbour several inclusion bodies like cyanophycin granules, polyhedral bodies, polyglucan granules, lipid granules, and polyphosphate granules, which have different functions.