Recent progress in metabolic engineering for the production of biofuels and biochemicals from renewable sources with particular emphasis on catabolite regulation and its modulation

• Recent metabolic engineering practice for the production of a variety of biofuels and biochemicals from renewable resources such as lingo-cellulose was reviewed.
• Catabolite regulation of Escherichia coli was paid attention from the point of view of co-consumption of multiple carbon sources obtained from lingo-cellulose, etc.
• The metabolic engineering practice by the introduction of heterologous genes from other organisms was also explained.

Recent metabolic engineering practice was briefly reviewed including the case where a mixture of multiple sugars obtained from lignocellulose, etc. was used as a carbon source to produce a variety of biofuels and biochemicals for the realization of green society. In the wild type Escherichia coli, sequential utilization of carbon sources is observed as known as diauxie phenomenon due to carbon catabolite repression (CCR), where much attention has been focused on co-consumption of multiple sugars to improve the productivities of the target metabolites. Although co-consumption of multiple sugars can be attained by modulating phosphotransferase system (PTS) and mgsA, pgi, etc. in E. coli, the glucose uptake rate inherently became lower, and thus the productivity of such metabolite as ethanol may not be improved, where this may be improved by amplifying the non-PTS pathway genes such as galP and glk. It should be noted that the modulation of PTS gene might change the robustness from the systems biology point of view.