Exploration of cell lysis in a bioreactor using Escherichia coli expressing single-chain variable-domain antibody fragments

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• 作者：Xiuxia Liu ; Weiguo Hu ; Zhanfei An ; Zhonghu Bai ; Xiaofeng Dai…
• 刊名：Annals of Microbiology
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：66
• 期：3
• 页码：1207-1215
• 全文大小：763 KB
• 刊物主题：Microbiology; Microbial Genetics and Genomics; Microbial Ecology; Fungus Genetics; Medical Microbiology; Applied Microbiology;
• 出版者：Springer Berlin Heidelberg
• ISSN：1869-2044
• 卷排序：66

文摘

Cell lysis has long been a process problem in protein expression using bacterial hosts. To explore the pathways involved in cell lysis in a bioreactor, Escherichia coli strain W3110 was used as the host to express single-chain variable-domain antibody fragments (scFv). Under the same fermentation conditions, E. coli strain W3110 expressing a humanized scFv entered the viable but nonculturable (VBNC) state 6 h before the wild-type strain, and the accumulation of the scFv within the cells accelerated cell lysis. At the transcriptional level, the scFv not only altered the expression of rpoH, dnaK, dnaJ, groES, and groEL in the heat stress response, but also rpoS, gadE, and gadX in the acid stress response pathway and sodA and katE in the oxygen stress response pathway. During cell lysis in a fermenter, the expression of the membrane protein-encoding genes ompA, ompC, ompW, and ompX significantly decreased, and the high-level expression of rpoE was not sustained. These findings provide new insights into cell lysis as well as a theoretical foundation for improving fermentation conditions and engineering bacteria to minimize cell lysis during fermentation.KeywordsBioreactorEngineering cell lysisσE pathwayStress responseViable but nonculturable