title: A study of high cell density cultivation process of recombinant Helicobacter pylori multi-epitope vaccine engineering bacteria.
abstract: OBJECTIVE
  To establish high cell density cultivation process of recombinant Helicobacter pylori multi-epitope vaccine engineering bacteria BIB.
  
  
  METHODS
  Based on the results of shake flask fermentation, the process was magnified into volume of a 50 L fermenter to optimize and verify the factors affecting the yield of the target protein, such as the fermentation medium, working seed inoculation amount, inducer concentration, induction starting time, induction duration, inducer adding mode and feeding strategy.
  
  
  RESULTS
  After activated in modified TB medium at 37°C for 8 h, the BIB working seed was inoculated at 5% (v/v) and was induced for expression for another 11 h by the final concentration of 5 mmol/L lactose. In growth phase, glucose at rate of 80 ml/h was used as carbon source, and in induction phase, glycerol at rate of 40 ml/h was used as carbon source; ammonia water was added dropwise to control pH at about 7.0, and revolution speed is adjusted to control the dissolved oxygen at above 30%; ultimately the output of bacterial body was 70 g/L and protein expression amount was about 32%.
  
  
  CONCLUSIONS
  After high cell density cultivation of the recombinant engineering bacteria, expression and yield of the target protein rBIB significantly increased.
authors.affiliation: Department of Medical Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University Chengdu, Sichuan 610041, P.R. China ; Department of Infectious Disease, Renmin Hospital, Hubei University of Medicine Shiyan, Hubei 442000, P.R. China ; Sichuan Vaccine Technology Co., Ltd. Chengdu, Sichuan 610041, P.R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Medical Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University Chengdu, Sichuan 610041, P.R. China ; Sichuan Vaccine Technology Co., Ltd. Chengdu, Sichuan 610041, P.R. China.
authors.forename: Xing
authors.initials: X
authors.lastname: Pan
authors.affiliation: Department of Medical Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University Chengdu, Sichuan 610041, P.R. China.
authors.forename: Hongren
authors.initials: H
authors.lastname: Wang
authors.affiliation: Sichuan Vaccine Technology Co., Ltd. Chengdu, Sichuan 610041, P.R. China.
authors.forename: Lizhen
authors.initials: L
authors.lastname: Gao
authors.affiliation: Sichuan Vaccine Technology Co., Ltd. Chengdu, Sichuan 610041, P.R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Sichuan Vaccine Technology Co., Ltd. Chengdu, Sichuan 610041, P.R. China.
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Medical Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University Chengdu, Sichuan 610041, P.R. China.
authors.forename: Wanyi
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Medical Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University Chengdu, Sichuan 610041, P.R. China.
authors.forename: Mingyuan
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Medical Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University Chengdu, Sichuan 610041, P.R. China.
authors.forename: Baoning
authors.initials: B
authors.lastname: Wang
keywords: HCDC; Helicobacter pylori; Hp; engineering bacteria; high cell density cultivation; multi-epitope vaccine