ISSN:
1432-0614
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Summary The expression of many secreted recombinant proteins in Gram-negative bacteria is limited by degradation in the periplasmic space. We have previously shown that the production of protein A-β-lactamase, a secreted fusion protein highly sensitive to proteolysis in Escherichia coli, can be increased in mutant strains deficient in up to three cell-envelope-associated proteolytic activities. In this work we investigated the effect of fermentation conditions on suppressing any residual proteolytic activity in various protease-deficient strains. Optimal production of the fusion protein was observed in cells grown under mildly acidic conditions (5.5≤pH≤6.0) and at low temperatures. These conditios were shown to specifically decrease the rate of proteolysis. In addition, a further increase in production was observed in cultures supplemented with 0.5 to 0.75 mM zinc chloride. This may relate to the inhibition of a cell envelope protease by Zn2+ ions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00164691
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