木质纤维素水解抑制物耐受基因筛选和鉴定

Screening and Identification of Genes Contributes to Tolerance Inhibitors Derived from Lignocellulose Hydrolysis

以竹屑、秸秆等为代表的木质纤维素原料用于生产燃料乙醇近年来备受关注,但是在水解过程中会产生大量的毒性物质会抑制酿酒酵母的乙醇发酵。为了不增加生产成本,提高毒性抑制物在应激条件下的发酵效率,筛选酿酒酵母中对这些抑制物广谱耐受基因至关重要。通过全基因组敲除文库扫描、生物信息学分析和基因回补验证,筛选出了酿酒酵母中对代表性抑制物糠醛、苯酚、乙酸以及三者混合抑制剂耐受的共有基因,分别是ASC1、ISC1、DRS2、RIC1、RPE1、YPT6、SEC66和ERG2;根据基因功能分析,明确了转录调控、信号转导、氧化应激耐受、麦角甾醇生物合成、自噬和内吞作用等蛋白与木质纤维素水解液复合抑制剂耐受相关。研究结果对燃料乙醇发酵的工程菌株改造具有重要借鉴意义。

In recent years,lignocellulose,represented by bamboo chips and straw,has been widely applied to produce bioethanol.However,a series of toxic inhibitors derived from the hydrolysis process will inhibit the fermentation of ethanol in Saccharomyces cerevisiae.To improve the fermentation efficiency under the stress of toxic inhibitors without increasing the production cost,it is the key to screen the genes in S.cerevisiae that contribute to tolerance these inhibitors in a broad range.Due to whole-genome knockout library scanning,bioinformatics analysis and gene complement verification,this study screened the common genes,namely ASC1,ISC1,DRS2,RIC1,RPE1,YPT6,SEC66 and ERG2,in S.cerevisiae that contribute to tolerance the representative inhibitors,such as furfural,phenol,acetic acid and their mixed inhibitors.According to function analysis of genes,it is identified that the proteins in transcription regulation,signal transduction,oxidative stress tolerance,ergosterol biosynthesis,autophagy and endocytosis are related to the tolerance of complex inhibitors derived from lignocellulose hydrolysate.It has important reference significance for transformation of the engineering strain for bioethanol fermentation.