Improving an Alternative Glycerol Catabolism Pathway in Yarrowia lipolytica to Enhance Erythritol Production.

Engineering the glycerol‐3‐phosphate pathway could enhance erythritol production by accelerating glycerol uptake. However, little work has been conducted on the alternative dihydroxyacetone (DHA) pathway in Yarrowia lipolytica. Herein, this route was identified and characterized in Y. lipolytica by metabolomic and transcriptomic analysis. Moreover, the reaction catalyzed by dihydroxyacetone kinase encoded by dak2 was identified as the rate‐limiting step. By combining NHEJ‐mediated insertion mutagenesis with a push‐and‐pull strategy, Y. lipolytica strains with high‐yield erythritol synthesis from glycerol were obtained. Screening of a library of insertion mutants allows the identification of a mutant with fourfold increased erythritol production. Overexpression of DAK2 and glycerol dehydrogenase GCY3 together with gene encoding transketolase and transaldolase from the nonoxidative part of the pentose phosphate pathway led to a strain with further increased productivity with a titer of 53.1 g/L and a yield 0.56 g/g glycerol, which were 8.1‐ and 4.2‐fold of starting strain. Take Away: The genes involved in the alternative dihydroxyacetone route were detected and then analyzed by GC/MS and RNA‐seq studies.Dihydroxyacetone kinase DAK2 catalyzes the rate‐limited step in the alternative glycerol uptake route.Diverse Yarrowia lipolytica strains had different adaptability to the alternative glycerol uptake route.53.1 g/L of erythritol production and a yield of 0.56 g/g glycerol were achieved by performing a push‐pull strategy in Yarrowia lipolytica M09. [ABSTRACT FROM AUTHOR]