Enhancing NADPH regeneration and increasing hydroxylation efficiency with P450 monooxygenase through strengthening expression of glucose-6-phosphate dehydrogenase in industrial filamentous fungi

Cytochrome P450 monooxygenases are a unique family of enzymes that are able to catalyze regio- and stereospecific oxidations for a broad substrate range. However, their highly-effective industrial application is often limited by the regeneration of cofactor NADPH. In this study, G6PDH from Rhizopus oryzae was expressed to enhance the regeneration of NADPH in the industrial strain, R. nigricans. The results showed the fermentation time of the engineered strain was shortened to 52 h when the hydroxylation yields reached the maximum, which was 4 h ahead compared to that of the original strain. 95.4%-higher-level NADPH could be generated and the hydroxylation yield increased by 15.6% in an engineered strain after 52-h fermentation compared to those in the original strain after 56-h fermentation. The results indicated that the strategy of enhancing NADPH regeneration by expressing G6PDH was simple and effective on improving the P450-monooxygenase-dependent hydroxylation ability in filamentous fungi.