Productivity of biomass and some metabolites of Anabaena oryzae and Nostoc sp. grown under stress conditions

The current study aimed to investigate the effect of stress conditions such as nitrogen
and phosphorous deficiency and supplementation, salinity stress and different pH
values on the biomass, lipid, protein, amino acid and carbohydrate productivities of
Anabaena oryzae and Nostoc sp. The obtained results revealed that an increase in
sodium nitrate by 100% led to increase in the productivities of biomass, protein and
amino acid of A. oryzae and Nostoc sp. While 100% nitrogen deficiency enhanced lipid
productivity to 40.8% and 48.7% for A. oryzae and Nostoc sp., respectively. In addition,
phosphorus limitation led to a reduction in biomass, lipid, amino acid and
carbohydrate for A. oryzae to 36%, 48.4%, 59.3% and 20%, respectively. However,
phosphorus free medium showed an increase in lipid productivity by 35% over the
control in Nostoc sp. Application of all concentrations of NaCl decreased the
productivities of all metabolites in A. oryzae. While high concentration (0.3M) of NaCl
enhanced carbohydrate productivity to 127.2% for Nostoc sp. In addition, the biomass
productivity of A. oryzae and Nostoc sp. was increased at pH 7 and at pH 8,
respectively. The maximum production of amino acid in A. oryzae and Nostoc sp. was
obtained at pH 8. On the other hand, the acidic and alkaline conditions did not cause
any significant changes on the productivity of carbohydrate in case of A. oryzae and
Nostoc sp