Combinatorial Engineering of Yarrowia lipolytica as a Promising Cell Biorefinery Platform for the de novo Production of Multi-Purpose Long Chain Dicarboxylic Acids

Abstract

This proof-of-concept study establishes Yarrowia lipolytica (Y. lipolytica) as a whole cell factory for the de novo production of long chain dicarboxylic acid (LCDCA-16 and 18) using glycerol as the sole source of carbon. Modification of the fatty acid metabolism pathway enabled creating a pool of fatty acids in a β-oxidation deficient strain. We then selectively upregulated the native fatty acid ω-oxidation pathway for the enhanced terminal oxidation of the endogenous fatty acid precursors. Nitrogen-limiting conditions and leucine supplementation were employed to induce fatty acid biosynthesis in an engineered Leu− modified strain. Our genetic engineering strategy allowed a minimum production of 330 mg/L LCDCAs in shake flask. Scale up to a 1-L bioreactor increased the titer to 3.49 g/L. Our engineered yeast also produced citric acid as a major by-product at a titer of 39.2 g/L. These results provide basis for developing Y. lipolytica as a safe biorefinery platform for the sustainable production of high-value LCDCAs from non-oily feedstock.

Keywords

• Yarrowia lipolytica
• long chain dicarboxylic acid
• building blocks
• citric acid
• glycerol
• genetic and metabolic engineering
• fermentation
• bioconversion