The outer membrane of lipid A-deficient Escherichia coli mutant LH530 has reduced levels of OmpF and leaks periplasmic enzymes.

We have previously described a new Escherichia coli K-12 mutant, LH530, which has a defective outer membrane. LH530 is very sensitive to hydrophobic antibiotics, does not grow at 42 degrees C and synthesizes reduced amounts of lipid A. Phenotypically LH530 is very similar to the known lipid A biosynthesis mutants of E.

The lipid A biosynthesis deficiency of the Escherichia coli antibiotic-supersensitive mutant LH530 is suppressed by a novel locus, ORF195.

A new mutant of Escherichia coli K-12 supersensitive to both hydrophobic and large hydrophilic antibiotics was isolated and characterized. The mutant grew well at 28 degrees C, poorly at 37 degrees C, and did not grow at 42 degrees C. The rate of its lipid A biosynthesis was reduced as compared to that of the parent strain.