effect of various nitrogen sources upon the production of extracellular polysaccharide by the blue-green alga Anabaena flos-aquae A-37

Anabaena flos-aquae A-37 was grown in bacteria-free culture on a variety of nitrogen sources. Extracellular polysaccharide production was found to be a part of the normal metabolic processes causing the liberation of excess carbohydrates into the surrounding medium rather than the result of cellular lysis. Non-adapted cells supplied with NH4Cl produced abundant polysaccharide. However, the population did not increase. Cells adapted to NH4Cl produced smaller quantities of polysaccharide, but the population did increase. Polysaccharide production per cell was similar on Mg(NO3)2, KNO3, NaNO3, NH4NO3, and NH4Cl. It was concluded that an adequately utilized nitrogen source does not affect polysaccharide production in A. flos-aquae A-37.