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Stabilizing plasmid copy number to improve recombinant protein production
Author(s) -
Grabherr Reingard,
Nilsson Erik,
Striedner Gerald,
Bayer Karl
Publication year - 2001
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.10104
Subject(s) - plasmid , bioprocess , recombinant dna , biology , cole1 , rna , gene , bacteria , gene expression , protein biosynthesis , microbiology and biotechnology , computational biology , genetics , paleontology
The key objective for recombinant protein production in bacteria is the maximum exploitation of the cell factory's potential, whereby often strong expression vectors are used to increase product yield. If the metabolic load caused by recombinant expression exceeds the host's capacity, the system exhausts itself, resulting in a loss of protein yield. Excessive plasmid replication is observed after inducing recombinant gene expression, which greatly contributes to metabolic overload of the host cell. The transcriptional and translational machineries are extremely overstrained. By abolishing sequence homology between Col E1 RNA I/RNA II and tRNAs, we were able to restore the plasmid's replication control mechanisms and to keep the plasmid copy number constant throughout the culture process, thereby prolonging metabolic activity and productivity of the bacterial expression system. Because the bacterial host cell is not being exploited beyond its tolerable potential with this method, the constancy of the plasmid copy number level throughout the whole period of the bioprocess provides novel strategies for bioprocess optimization. © 2002 John Wiley & Sons, Inc. Biotechnol Bioeng 77: 142–147, 2002.