STRUCTURAL ORGANIZATION OF MEMBRANES IN PLASMID-CONTAINING AND PLASMID-FREE SALMONELLA DERBY CELLS - ROLE OF PHOSPHOLIPIDS AND PHOSPHOLIPIDFATTY-ACIDS

The effects of an R-plasmid on the phospholipid and fatty-acid composi tions of Salmonella derby cells have been studied both quantitatively and qualitatively. The absence of the R-plasmid dramatically decreased the content of phospholipids, particularly phosphatidylcholines. This change was associated with an increase in the percentage of lysophosp hatidylcholines. The proportion of saturated and unsaturated fatty aci ds in plasmid-free cells was nearly the same as in their plasmid-conta ining counterparts. Increased lipid peroxidation occurred in the plasm id-free S. derby strain even though the content of alpha-tocopherol in these bacteria was relatively high.