Metabolic Engineering Prospects for Enhanced Green Fuel Production by Microalgae

Abstract

The world has been entering into a phase of acute energy crisis due to the loga- rithmic increase in global population and the continuous depletion of finite fossil fuel resources. Generation of greenhouse gasses due to combustion of fossil fuels adds further menace to the environment bringing about global warming. There is an urgent need to search for an alternative fuel source which is economic and environmental friendly. Microalgae are the photosynthetic microorganisms which have the potential to convert light energy into biofuel through series of biochemical reactions. However, the major drawbacks for algae-based biofuel production are the time-consuming processes. According to a report published by US Department of Energy, there are 3000 different microalgae having poten- tial to produce TAG as main precursor of biofuel. There are several genes which encode enzymes for the lipid metabolism responsible for enhancing the lipid content in microalgae. Development of molecular tools and techniques and syn- thetic biology may give more insight into the synthesis of triacylglycerides (TAG) in lipid-accumulating microalgae. In this article, we review the possibility of development of metabolic engineering for lipid synthesis in microalgae and discuss the various strategies such as single gene expression, carbon assimila- tion, expression of transcription factors and flux balance analysis which increase the lipid accumulation via metabolic engineering. R.