Alkalihalophilic alga Picocystis salinarum SLJS6 from Sambhar Salt Lake: Potential for bicarbonate-based biomass production and carbon capture

Abstract

An extremely alkalihalophilic picoalgal strain, Picocystis salinarum SLJS6 isolated from Sambhar salt lake, Rajasthan, India, was evaluated for its suitability for bicarbonate based carbon capture and biomass production. The isolate was characterized in terms of growth attributes, tolerance to salinity, high dissolved inorganic carbon (DIC) concentration and carbon fixation rates. The isolate grew robustly in a medium containing mainly Na2CO3, 50 g/L, NaHCO3, 50 g/L, NaCl, 50 g/L (salinity ≈150 ‰, DIC ≈ 1 M NaHCO3/Na2CO3) at pH 10, achieving a growth rate of 0.2282 day−1, biomass productivity of 0.498 g/L/day (>35 folds as compared to low DIC and salinity) and CO2 fixation rate of 0.729 g/L/day. Based on a rapid colorimetric method, the average total lipid content of SLJS6 was found to be 226.9 mg/g DW. Thus, P. salinarum SLJS6 is a promising candidate for bicarbonate-based CO2 capture and recycling.