Conversion of saturated fatty acid to unsaturated one: Whole-cell catalysis of Saccharomyces cerevisiae

New production technology for functional unsaturated fatty acids such as DHA, EPA, ARA, and POA (palmitoleic acid) is urgently required. Here we developed a whole-cell catalysis method to convert low-value fatty acids to high-value one by using Saccharomyces cerevisiae as whole-cell biocatalyst. Results showed that palmitic acid was the most appropriate substrate for the bioconversion, and it increased the production of POA by 17.0% in comparison with de novo synthesis by fermentation only. A thorough investigation on the primary bioconversion conditions was performed. Under the optimum parameters, the substrate utilization rate reached 96.1%, which resulted in the production of POA increased to 5.9 g L-1, 90.3% higher than that of fermentation only. Stable isotope analysis showed that up to 61.7% of substrate was catalyzed to POA. Transcriptomic analysis revealed a repression from glucose to lipid but an acceleration from lipidic substrate to POA in S. cerevisiae during wholecell catalysis.

Automated summary

A whole-cell catalysis method using Saccharomyces cerevisiae as a biocatalyst was developed to convert low-value fatty acids to high-value ones. Palmitic acid was found to be the most suitable substrate, increasing the production of palmitoleic acid (POA) by 17.0% compared to de novo synthesis. Under optimal conditions, substrate utilization rate reached 96.1%, resulting in a 90.3% increase in POA production compared to fermentation only. Stable isotope analysis revealed that up to 61.7% of the substrate was catalyzed to POA. Transcriptomic analysis showed a repression of glucose to lipid but an acceleration from lipidic substrate to POA in S. cerevisiae during whole-cell catalysis.