Enhancement of Growth and Lipid Accumulation by Chlorella sorokiniana 1019 under Mixotrophic Culture Conditions

Abstract

The enhancement of the growth and lipid accumulation by a microalga, Chlorella sorokiniana 1019, was investigated under mixotrophic conditions. The results showed that the growth and lipid production in this alga were notably increased under mixotrophic conditions using a limited-nitrogen medium compared to phototrophic and heterotrophic conditions. The biomass yield and lipid production were approximately 3.9 and 2.6 times more than under phototrophic growth. Among the three carbon sources of glucose, potassium acetate and glycerol, 1% glucose promoted the highest growth rate at 7.58 g of cell dry weight.L-1 after 7 d of cultivation, while 3% acetate yielded the highest cellular lipid reaching 56% of the dried biomass. The fatty acid composition of the alga was slightly changed from the predominant linoleic acid in the glucose medium to palmitic acid in the acetate medium.