Lipid accumulation by a novel microalga Parachlorella kessleri R-3 with wide pH tolerance for promising biodiesel production

In this study, a new microalgal strain was isolated and identified as Parachlorella kessleri R-3, which could utilize a variety of organic and inorganic carbon and nitrogen sources. More importantly, it was found that strain R-3 can accumulate large amount of biomass and lipids in a wide pH range from 3 to 11, and it can gradually adjust the pH of the medium to near neutrality during the cultivation. At the optimal glucose concentration of 10 g L−1, sodium nitrate concentration of 0.8 g L−1 and initial pH of 7, the highest algal biomass of 6.90 g L−1, lipid content of 45.12 % and lipid productivity of 340.94 mg L−1 d−1 were achieved. In addition, C16:0 iso 3OH and C16:1 w7c alcohol were the predominant fatty acids components, which accounted for as high as 88.04 %. These showed the potential of the new microalgal strain for application in biodiesel production.