Enhanced pyruvic acid yield in an osmotic stress-resistant mutant of Yarrowia lipolytica

Abstract

Background: Pyruvic acid (PA), a vital α-oxocarboxylic acid, plays an important role in energy and carbon metabolism. The oleaginous yeast Yarrowia lipolytica (Y. lipolytica) has considerable potential for the production of PA. An increased NaCl concentration reportedly increases the biomass and PA yield of Y. lipolytica. Results: To increase the yield of PA, the NaCl-tolerant Y. lipolytica A4 mutant was produced using the atmospheric and room temperature plasma method of mutation. The A4 mutant showed growth on medium containing 160 g/L NaCl. The PA yield of the A4 mutant reached 97.2 g/L at 120 h (0.795 g/g glycerol) in a 20-L fermenter with glycerol as the sole carbon source, which was 28.9% higher than that of the parental strain. Conclusion: The PA yield from Y. lipolytica can be improved by increasing its NaCl tolerance. Keywords: ARTP, Fermentation, Glycerol, NaCl tolerance, oleaginous yeast, Pyruvic acid, Yarrowia lipolytica, yeast mutagenesis