The enhancement of growth, biomass production and lipid productivity of microalgae Choricystis sp. LBB13-AL045 by the addition of hot water extract of its dried biomass

This study sought to evaluate the influence of hot water extract addition on cell growth, biomass production and lipid productivity during cultivation of microalgae Choricystis sp. LBB13-AL045 under different light intensity. The cellular growth of microalgae in terms of growth rate and produced biomass increased significantly with the addition of hot water extract into the microalgal culture under both low- and high-light intensity (3000 and 30000 lux, respectively), demonstrating that hot water extract of microalgal biomass positively interferes with the metabolism of microalgae and the production of biomass. Thus, microalgal lipid productivity was eventually increased almost three times when hot water extract (7,5 mg/mL) was employed in the microalgal cultivation with high light intensity. Hot water extract was prepared by the autoclaving varied concentration of dried microalgal biomass (2,5-7,5 mg/mL) in water. The cultivation of Choricystis sp. LBB13-AL045 showed the highest net increase of biomass production (975,05 mg) at hot water extract concentration of 7,5 mg/mL and light intensity of 30000 lux. The current investigation demonstrates that hot water extract of Choricystis's dried biomass accelerate its growth and induce its lipid productivity for its application in biodiesel production.