Engineering Saccharomyces cerevisiae for the production of punicic acid-rich yeast biomass

Punicic acid (PuA), an unusual conjugated linolenic acid found in pomegranate, offers diverse health benefits and potential applications in the food industry. The limited production of PuA from its natural plant sources has led to a growing interest in producing it through microbial fermentation. In this study, the "generally recognized as safe" yeast Saccharomyces cerevisiae was engineered to produce PuA. Candidate genes related to PuA synthesis were directly shuffled within the yeast genome. Subsequent screening and optimization resulted in a strain that synthesized 26.7% of its total fatty acids as PuA. Further analyses revealed that the strains storage lipids contained over 22% PuA. By incorporating the health-promoting lipid component into the nutritional profile of S. cerevisiae, the engineered strain could potentially serve as a sustainable source of yeast biomass with enhanced nutritional value.