The phosphoglyceride composition of gram-negative bacteria and the changes in composition during growth

Abstract

1. 1. With one exception, Agrobacterium tumefaciens in stationary growth phase, phosphatidylethanolamine was the major phospholipid present at all stages of growth in 8 species of Gram-negative bacteria studied. Phosphatidylglycerol and diphosphatidylglycerol were also always present. 2. 2. The species studied could otherwise be divided into two groups on the basis of whether N- methyl derivatives of phosphatidylethanolamine were also present. This classification and the discrimination of two additional groups on the basis of published reports are discussed. 3. 3. In addition to the major lipids indicated above, phosphatidic acid was also generally detected and phosphatidylglycerol phosphate was found in measurable amounts in some strains. 4. 4. With a few exceptions, phosphatidylethanolamine, phosphatidylglycerol, phosphatidyl- N- monomethylethanolamine and phosphatidylcholine rise to a maximum concentration in late log or early stationary phase and then decrease in concentration. Diphosphatidylglycerol rises during the transition between log and stationary phase and then increases to a maximum concentration in stationary phase.