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 β-lactamase production in continuous culture without selective pressure.
|Original language||English (US)|
|Number of pages||7|
|State||Published - Jan 1 1990|
All Science Journal Classification (ASJC) codes
- Applied Microbiology and Biotechnology
- Molecular Medicine
- Biomedical Engineering