Developing controllable hypermutable Clostridium cells through manipulating its methyl-directed mismatch repair system  

作　　者：Guodong Luan Zhen Cai Fuyu Gong Hongjun Dong Zhao Lin Yanping Zhang Yin Li 

机构地区：[1]CAS Key Laboratory of Microbial Physiological and Metabolic Engineering,Institute of Microbiology,Chinese Academy of Sciences,Beijing 100101,China [2]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Protein & Cell》2013年第11期854-862,共9页蛋白质与细胞（英文版）

基　　金：the National Natural Science Foundation of China(Grant No.31270107);the National Basic Research Program of China(973 Program)(No.2011CBA00800);the National High Technology Research and Development Program(863 Program)(No.2011AA02A208);the Knowledge Innovation Program of the Chinese Acad-emy of Sciences(No.KSCX2-EW-Q-14).

摘　　要：Development of controllable hypermutable cells can greatly benefit understanding and harnessing microbial evolution.However,there have not been any similar sys-tems developed for Clostridium,an important bacterial genus.Here we report a novel two-step strategy for de-veloping controllable hypermutable cells of Clostridium acetobutylicum,an important and representative indus-trial strain.Firstly,the mutS/L operon essential for methyl-directed mismatch repair(MMR)activity was inactivated from the genome of C.acetobutylicum to generate hy-permutable cells with over 250-fold increased mutation rates.Secondly,a proofreading control system carrying an inducibly expressed mutS/L operon was constructed.The hypermutable cells and the proofreading control system were integrated to form a controllable hypermut-able system SMBMutC,of which the mutation rates can be regulated by the concentration of anhydrotetracycline(aTc).Duplication of the miniPthl-tetR module of the proof-reading control system further signifi cantly expanded the regulatory space of the mutation rates,demonstrating hypermutable Clostridium cells with controllable mutation rates are generated.The developed C.acetobutylicum strain SMBMutC2 showed higher survival capacities than the control strain facing butanol-stress,indicating greatly increased evolvability and adaptability of the controllable hypermutable cells under environmental challenges.

关 键 词：Clostridium acetobutylicum mutation rates hypermutable cells artifi cial control 

分 类 号：R73[医药卫生—肿瘤]