Use of the Escherichia coli SSB gene to prevent bioreactor takeover by plasmidless cells.
Reactor takeover by plasmidless cells is a major problem encountered when producing proteins from plasmid-borne genes in genetically engineered bacteria. We have approached this problem by deleting the essential ssb gene from the Escherichia coli chromosome and placing it on a plasmid. Plasmidless cells do not accumulate even after growing such strains under non-selective continuous culture conditions for extended periods of time. Other ssb-containing plasmids can be readily introduced into this E. coli strain by a plasmid-displacement technique. Using this system, we have achieved very high levels of beta-lactamase production in continuous culture without selective pressure.
Department of Molecular and Cell Biology, Pennsylvania State University, University Park 16802.
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Porter
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Black
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Pannuri
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Carlson
D001426:Bacterial Proteins / Q000235:genetics; D015139:Blotting, Southern; D002872:Chromosome Deletion; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development; D005798:Genes, Bacterial; D005821:Genetic Techniques; D010957:Plasmids; D001618:beta-Lactamases / Q000096:biosynthesis
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D001618:beta-Lactamases