Impact of combined nitrogen sources on growth and synthesis of bioactive compounds in Synechococcus elongatus Nägeli, a coccoid cyanobacterium

The present communication deals with the effect of different combined nitrogen sources viz. urea, ammonium chloride, sodium nitrate and potassium nitrate as a sole nitrogen source on the growth of Synechococcus elongatus. The effect of different nitrogen sources were evaluated on the basis of biomass, growth rate, generation time and biological carbon sequestration. Study was conducted on the synthesis of primary, accessory photosynthetic pigments and photo-protective pigment under semi-continuous influence of different sources of combined nitrogen. Sodium nitrate in the nutrient medium could proliferate growth rate and lower generation time of S. elongatus and it is also responsible for maximum biological carbon sequestration, synthesis of bioactive compounds like chlorophyll-a, carotenoids and phycobilins. Potassium nitrate as a sole nitrogen source could be responsible for enhanced production of total protein in S. elongatus cells. On evaluation of all four different nitrogen sources it could be concluded that sodium nitrate is the best source of nitrogen while urea could be toxic for S. elongatus.