Enhanced Lipid Accumulation by Chlorella vulgaris in a Two-Stage Fed-Batch Culture with Glycerol

Abstract

A large amount of crude glycerol is generated during biodiesel production, but it has little commercial value. In this study, glycerol was used to cultivate Chlorella vulgaris to recycle its surplus, and its effects on microalgal growth and lipid accumulation were investigated. Lipid production in glycerol batch culture was higher than in glucose batch culture. However, the cell growth was slow, and a lag phase was more obvious as glycerol concentration increased from 1 to 30 g L–1. A two-stage fed-batch culture was developed to achieve high cell density and lipid production in C. vulgaris. In this culture, high microalgal cell concentration was first obtained by glucose, and lipid accumulation was enhanced by later additions of crude glycerol. Lipid production and lipid content reached 1663.02 mg L–1 and 36.39%, respectively. Lipids produced by C. vulgaris were good feedstock for biodiesel production.