New xylose transporters support the simultaneous consumption of glucose and xylose in Escherichia coli  

作　　者：Xinna Zhu Feiyu Fan Huanna Qiu Mengyao Shao Di Li Yong Yu Changhao Bi Xueli Zhang 

机构地区：[1]Tianjin Institute of Industrial Biotechnology,Chinese Academy of Sciences,Tianjin,China [2]Key Laboratory of Systems Microbial Biotechnology,Chinese Academy of Sciences,Tianjin,China [3]College of Biotechnology,Tianjin University of Sciences and Technology,Tianjin,China [4]University of Chinese Academy of Sciences,Beijing,China

出　　处：《mLife》2022年第2期156-170,共15页微生物（英文）

基　　金：supported by grants from National Key R&D Program of China(2019YFA0904900);National Natural Science Foundation of China(31870058).

摘　　要：Glucose and xylose are two major components of lignocellulose.Simultaneous consumption of glucose and xylose is critical for engineered microorganisms to produce fuels and chemicals from lignocellulosic biomass.Although many production limitations have been resolved,glucose‐induced inhibition of xylose transport remains a challenge.In this study,a cell growthbased screening strategy was designed to identify xylose transporters uninhibited by glucose.The glucose pathway was genetically blocked in Escherichia coli so that glucose functions only as an inhibitor and cells need xylose as the carbon source for survival.Through adaptive evolution,omics analysis and reverse metabolic engineering,a new phosphoenolpyruvate:carbohydrate phosphotransferase system(PTS)galactitol transporter(GalABC,encoded by EcolC_1640,EcolC_1641,and EcolC_1642 genes)that is not inhibited by glucose was identified.Inactivation of adenylate cyclase led to increased expression of the EcolC_1642 gene,and a point mutation in gene EcolC_1642(N13S)further enhanced xylose transport.During the second round of gene mining,AraE and a new ABC transporter(AraFGH)of xylose were identified.A point mutation in the transcription regulator araC(L156I)caused increased expression of araE and araFGH genes without arabinose induction,and a point mutation in araE(D223Y)further enhanced xylose transport.These newly identified xylose transporters can support the simultaneous consumption of glucose and xylose and have potential use in producing chemicals from lignocellulose.

关 键 词：ABC transporter GLUCOSE PTS XYLOSE xylose transporter 

分 类 号：Q93[生物学—微生物学]