Disrupting a phospholipase A2 gene increasing lipid accumulation in the oleaginous yeast Yarrowia lipolytica

AIMS

Phospholipase A₂ (PLA₂ ) is a diverse superfamily that hydrolyzes fatty acyl ester bonds at the sn-2 position of phospholipids. The correlation between phospholipid metabolism and the anabolism of neutral lipids remains unclear in yeasts. This study aims to explore the effects of PLA₂ on lipid accumulation in the oleaginous yeast Yarrowia lipolytica.

METHODS AND RESULTS

This study identified an actively expressed phospholipase A₂ gene (PLA2-3, YAIL0_E16060g) in Y. lipolytica by quantitative PCR analysis. The gene PLA2-3 was disrupted in the strain po1gΔKu70 by homologous recombination and in the strain po1g-G3 by a CRISPR-Cas9 system, which caused an increase in stress sensitivity while the cell growth was not altered under fermentative conditions. Lipid production was performed in both flasks and bioreactors. The results showed that the lipid titre and lipid content were improved over 25% and 8-30%, respectively, in PLA2-3 disrupted strains compared to the controls.

CONCLUSIONS

Disruption of the phospholipase PLA2-3 gene could effectively improve lipid production in Y. lipolytica.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study presented a strategy on improving the lipid production of oleaginous yeasts and a similar strategy might be used in other oleaginous microbes.

TiO2-modified CNx nanowires as a Pt electrocatalyst support with high activity and durability for the oxygen reduction reaction

A Pt/TiO₂-modified carbon nitride nanofiber (Pt/TiO₂-CN_x) catalyst has been synthesized by a chemical method for the oxygen reduction reaction (ORR).