An effective approach of bacterial siderophore as nitrogen source triggering the desired biochemical changes in microalgae Chlorella variabilis ATCC 12198

The present study was aimed to check whether catecholate siderophore can serve as a nitrogen source besides iron for microalgae. Catecholate siderophore from Idiomarina loihiensis RS 14 contains 13% nitrogen which can be a potential nitrogen source. Bacterial supernatant containing siderophores with different inoculum ratio was used to check the growth of Chlorella variabilis ATCC 12198. Nitrogen starvation with two stage cultivation was employed here to trigger the accumulation of lipid and carbohydrate. In continuous cultivation, the highest productivity of DCW was observed in 1%, 760 mg/L compared to culture grown at 0.5%, with an increase of 42.2% higher biomass productivity (21.66 mg/L/day). Similarly, in 1%, C. variabilis produced total 30% of lipid content which contains 75% of neutral lipid. Highest carbohydrate was (49.29%) found in cells grown under 9 days of stress in 1% followed by cells grown under 3 days of stress in 5% (46.52%) in stage II cultivation.