Novel Codon-optimization Genes Encoded in Chlorella for Triacylglycerol Accumulation

Microalgae have been recognized as one of the potential resources for biodiesel production based on its fast growth or its high total lipid content depending on species. Expression of Kennedy pathway genes, which encodes GPAT, LPAAT, PAP, and DGAT for increasing the metabolic flux towards the TAG storage in Chlorella sp. from 20 to 46 wt% and total lipid accumulation from 35 to 60 wt.% corresponding to each specific gene combination under autotrophy, compare to the wild type (vector only). The highest TAG content was found in cells expressing a quadruple-gene construct (GPAT-LPAAT-PAP-DGAT) in the Kennedy pathway, corresponding to 46 wt.% of TAG and 60 wt.% of total lipid content. This work provides the optimization of TAG production in Chlorella sp. can be achieved by manipulating the selected genes, in turns making commercially producing biodiesel practical.