Improvement in γ-decalactone production by Yarrowia sp. after genome shuffling

Abstract

AbstractIn this study, a modified genome shuffling method was used to improve γ-decalactone (GDL) production of Yarrowia sp. China General Microbiological Culture Collection Center (CGMCC 2.1405). Five UV mutant strains with higher GDL production or shorter fermentation time were selected as the initial strains for genome shuffling. Conditions of protoplast preparation, regeneration, inactivation, fusion, sporulation of recombinant fusants and ascospore isolation were optimized. Four hereditarily stable haploid recombinants with high GDL production were obtained by three rounds of genome shuffling. Among them, a high GDL-producing recombinant, G3-3.21, producing 3.75 g L−1 of GDL in the fermentation medium after 64 h was obtained. This value is 6.54-fold higher than that of the parent strains CGMCC 2.1405, at the peak production shortened by 8 h. Mathematical kinetic models of CGMCC 2.1405 and G3-3.21 were established to well predict the cell growth and GDL production. The cell growth of G3-3.21 was significantly faster than that of CGMCC 2.1405. The product synthesis constant associated with the strain growth of G3-3.21 was higher than that associated with CGMCC 2.1405. Long-chain fatty-acyl-CoA oxidase activities of G3-3.21 were 833 mU mg−1 and 6.83 times higher than that of CGMCC 2.1405.