Overproduction of palmitoleic acid from corn stover hydrolysate by engineered Saccharomyces cerevisiae

Palmitoleic acid (POA) has been widely applied to nutrition and pharmaceutical industry. However, high cost of scale-up fermentation restricts the extensive application of POA. Hence, we investigated the availability of corn stover hydrolysate (CSH) as carbon source in POA production by engineered S. cerevisiae. Although the yeast growth was inhibited to some extent by CSH, the POA production with CSH was slightly higher than that with pure glucose. The C/N ratio of 120 and addition of 1 g/L lysine raised the POA titer up to 2.19 g/L and 2.05 g/L, respectively. Two-stage cultivation could increase the POA titer by upregulating the gene expression of key enzymes in fatty acid synthesis pathway. A high POA content of 57.5% (v/v) and a highest POA titer of 6.56 g/L were achieved under the optimized conditions. These findings provide a feasible approach for sustainable production of POA or its derivatives from CSH.

Automated summary

This study investigated the feasibility of using corn stover hydrolysate (CSH) as a carbon source for the production of palmitoleic acid (POA) by engineered S. cerevisiae. Although the growth of yeast was inhibited by CSH to some extent, the POA production with CSH was slightly higher than that with pure glucose. The C/N ratio of 120 and the addition of 1 g/L lysine increased the POA titer. Under optimized conditions, a high POA content of 57.5% (v/v) and a highest POA titer of 6.56 g/L were achieved.