Redirecting the lipid metabolism of the yeast Starmerella bombicola from glycolipid to fatty acid production. (1st December 2019)

• Record Type: Journal Article
• Authors: Jezierska, Sylwia; Claus, Silke; Ledesma-Amaro, Rodrigo; Van Bogaert, Inge
• Is Part Of: Journal of industrial microbiology & biotechnology. Volume 46:Number 12(2019)
• Page Start: 1697
• Page End: 1706
• Publication Date: 2019-12-01
• Subjects: Starmerella bombicola -- Yeast -- Free fatty acid -- Lipid metabolism -- Sophorolipid; Industrial microbiology -- Periodicals; 660.62
• DOI: 10.1007/s10295-019-02234-x
• Languages: English
• ISSNs: 1367-5435

Abstract

Abstract: Free fatty acids are basic oleochemicals implemented in a range of applications including surfactants, lubricants, paints, plastics, and cosmetics. Microbial fatty acid biosynthesis has gained much attention as it provides a sustainable alternative for petrol- and plant oil-derived chemicals. The yeast Starmerella bombicola is a microbial cell factory that naturally employs its powerful lipid metabolism for the production of the biodetergents sophorolipids (> 300 g/L). However, in this study we exploit the lipidic potential of S. bombicola and convert it from the glycolipid production platform into a free fatty acid cell factory. We used several metabolic engineering strategies to promote extracellular fatty acid accumulation which include blocking competing pathways (sophorolipid biosynthesis and β-oxidation) and preventing free fatty acid activation. The best producing mutant ( Δcyp52m1Δfaa1Δmfe2 ) secreted 0.933 g/L (± 0.04) free fatty acids with a majority of C18:1 (43.8%) followed by C18:0 and C16:0 (40.0 and 13.2%, respectively). Interestingly, deletion of SbFaa1 in a strain still producing sophorolipids also resulted in 25% increased de novo sophorolipid synthesis ( P = 0.0089) and when oil was supplemented to the same strain, a 50% increase in sophorolipid production was observed compared to the wild type ( P = 0.03). We believe that our work is pivotal for the further development and exploration of S. bombicola as a platform for synthesis of environmentally friendly oleochemicals.