Alga biomass was centrifugally collected (5000g, 10 min, 4 °C) and freeze dried, then the algal dry biomass was gravimetrically determined. The chlorophyll and b-carotenoid content of B. braunii were determined by extracting the algal cells with 90% (v/v) ace- tone solution and pectrophotometrically analyzing the pooled ex- tract at specific wavelengths (Ge et al., 2011). To estimate the hydrocarbon content, freeze-dried algal powder was firstly sonica- tly extracted for 30 min in 30 ml n-hexane, and then the superna- tant was collected and evaporated in a rotary evaporator at 32 °C. Finally, the remaining was measured gravimetrically as hydrocar- bon (Sawayama et al., 1992).