酿酒酵母异源合成己二酸

Production of adipic acid in recombinant Saccharomyces cerevisiae

以酿酒酵母(Saccharomyces cerevisiae)为底盘生物,将来源于嗜热菌Thermobifida fusca B6中的己二酸逆降解途径基因搭配不同的酿酒酵母组成型启动子和终止子,构建在3个穿梭质粒上,并导入宿主细胞,成功实现了己二酸的异源合成。将AA-1菌株在YPD培养基中发酵,得到3.39 mg/L己二酸,是同一宿主中已报道的最高值。同时,敲除了酿酒酵母TCA循环关键基因LSC1,但未能使己二酸产量提高。通过发酵实验,研究了生物量、副产物乙醇与己二酸产量的联系;并通过改变初始碳源浓度对乙醇和己二酸产量进行了研究,为进一步提高己二酸产率、降低酿酒酵母葡萄糖效应提供了参考依据。

The adipate synthesis pathway from Thermobifida fusca B6 was transformed into Saccharomyces cerevisiae for the first time and succeeded to synthesis adipic acid from glucose.Three shuttle plasmids harboring the pathway genes were combined with suitable constitutive promoters and terminators and introduced into S.cerevisiae.The titer,3.39 mg/L,was obtained by fermentation of AA-1 strain in YPD medium.To enhance the acceleration of succinyl-CoA from TCA cycle for adipic acid synthesis,the LSC1 gene was deleted.However,it failed to improve adipic acid titer.The relationship between adipic acid titer with the biomass and by-products ethanol was studied.Besides,the yield of ethanol and adipic acid was studied by changing the initial concentration of the carbon source.The results provided a reference for further improving the yield of adipic acid and reducing the Crabtree effect of S.cerevisiae.