Engineering microorganisms for biofuel production

Abstract

The current challenges faced in the development of advanced biofuels from cellulosic biomass include the inefficiency of the recombinant hosts to hydrolyze lignocellulose, incomplete utilization of multiple sugars due to the presence of carbon-catabolite repression, lack of suitable gene-expression systems for coordinating multiple-gene expression, difficulties in optimizing a synthetic metabolic pathway and toxicity of both the substrate (lignin) and the end product (biofuel) to the recombinant host. Despite the aforementioned hurdles, potential biofuels such as short- or long-chain alcohols, alkanes, fatty acid methyl esters and isoprenoid-based fuels have been produced by metabolically engineered hosts, but with no promising improvement in the yield. An economically feasible advanced biofuel could be possible with the recent advances in metabolic engineering, genome engineering and synthetic biology through a genetically modified microbe or a synthetic microbe with a well-defined metabolism.