The preparation of a hyper-thermostable whole-cell biocatalyst and its application for biosynthesis of biodiesel

摘要

In this study, a hyper-thermostable lipase whole-cell biocatalyst has been developed. The hydrolytic activity of the codon-optimized ROL displayed on the yeast cell surface was 19.5 U /g dried cells cultured in SD medium, while the biomass was 13 g/L. Moreover, the whole-cell biocatalyst presented great thermostability. After 10 min incubation at 90 °C, 95 °C and 100 °C, the residual activity of lipase still remained 89%, 86% and 68%, respectively. Therefore, the whole-cell biocatalyst was applied in bioconversion of FAME and biodiesel. In our study, 50 mM oleic acid was most reasonable for bioconversion of FAME, and 50 mM soy oil was most reasonable for bioconversion of biodiesel, when the reaction were carried out in hexane as the solvent, and the molar ratio of oleic acid (or soy oil) and methanol was 1:4. Reactions were catalyzed by 0.5 g lyophilized bioimprinted whole-cell biocatalyst and incubated at 45 °C for 12 h with shake.