Effect of R-plasmid RP1 and nutrient depletion on the gross cellular composition of Escherichia coli and its resistance to some uncoupling phenols.

The resistance of Escherichia coli batch cultures depleted of carbon (C-dep), magnesium (Mg-dep), or phosphate (P-dep) against low concentrations of 3-chlorophenol, 4-chlorophenol, or 2-phenoxyethanol varied. C-dep cultures were always significantly more sensitive than Mg-dep or P-dep cultures. The presence of R-plasmid RP1 increased the sensitivity of C-dep cultures to 3- and 4-chlorophenol, yet had little effect on those cultured depleted in magnesium or phosphate ions. Cultures with R-plasmid RP1 had increased levels of beta-polyhydroxybutyrate irrespective of the nature of the depleting nutrient. P-dep bacteria had less than one-third of the phospholipid of other cell types, this deficiency being compensated for by increases in fatty acid and neutral lipid content. The reduction in phospholipid content of P-dep cultures was entirely accounted for by decreased diphosphatidylglycerol and phosphatidylethanolamine levels in these cells.