Overexpression of glucose-6-phosphate dehydrogenase enhanced the polyunsaturated fatty acid composition of Aurantiochytrium sp. SD116

Aurantiochytrium sp. (Thraustochytriaceae, Stramenopiles) is a highly promising polyunsaturated fatty acid (PUFA) resource due to its high docosahexaenoic acid (DHA) production. The reducing agent NADPH is essential for the production of PUFA and other fatty acids, and glucose-6-phosphate dehydrogenase (G6PDH) is one of the most important enzymes for NADPH regeneration in Aurantiochytrium. To investigate whether PUFA production could be enhanced by stimulating G6PDH, a recombinant strain, termed SD116::G6PDH, was constructed by overexpressing G6PDH in Aurantiochytrium sp. SD116. Although decreased cell growth and fatty acid production were observed, G6PDH overexpression changed the fatty acid profile and enhanced the proportion of PUFA in lipids by 10.6%. These results confirmed the positive effect of G6PDH activity on PUFA production and suggested that the manipulation of NADPH production is a promising strategy for increasing PUFA production in Aurantiochytrium.