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Release of periplasmic enzymes and other physiological effects of β‐lactamase overproduction in Escherichia coli
Author(s) -
Georgiou George,
Shuler Michael L.,
Wilson David B.
Publication year - 1988
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.260320603
Subject(s) - periplasmic space , escherichia coli , lysis , lac operon , extracellular , overproduction , plasmid , enzyme , biochemistry , enterobacteriaceae , chemistry , bacterial outer membrane , biology , microbiology and biotechnology , gene
When Escherichia coli containing the plasmid ptac11 is induced with 10 −4 M isopropyl‐β‐thiogalactopyranoside (IPTG), 90% of the β‐lactamase activity of an overnight culture is present in the medium. The high extracellular activity of β‐lactamase does not result from cell lysis but from an increase in the permeability of the outer membrane. The excreting cells release several other periplasmic enzymes into the extracellular fluid and are more sensitive to lysis by detergents. It was also shown that in these cells the level of two membrane proteins, OmpA and OmpC, is decreased. None of these phenomena were observed with the plasmid pDW17, which has a mutation in the tac promoter that reduces its activity to one fourth of the tac promoter.