Abstract

Acetyl-CoA carboxylase (ACCase) is one of the key enzymes that participate in lipid biosynthesis; a detailed understanding of its regulation mechanism is of potential value for lipid production in oil-producing species. In this study, a 1.5 kb fragment of accD gene from Chlorella protothecoides FACHB-2 was cloned, and the expression levels of it under autotrophic and heterotrophic conditions were investigated through quantitative real-time PCR technique. The results show that the expression levels of accD gene under heterotrophic conditions were higher than under autotrophic conditions, higher at the stationary phases than at exponential phases, and accordingly the lipid contents increased significantly. So, it can be concluded that expression of ACCase gene plays an important role in regulating the lipid contents of Chlorella protothecoides FACHB-2 under different cultivation conditions.

Key words: Acetyl-CoA carboxylase, Chlorella protothecoides, lipid synthesis, quantitative real-time PCR, transcription.