Changes in the composition of membrane phospholipids during the cell cycle of Escherichia coli

Phospholipid concentrations have been estimated throughout the successive cell cycle in synchronously growing culture of E. coli B/r. Total phospholipid phosphorus was shown to be doubled in the period of time between two cell divisions, whereas during the division itself it did not change. Phosphatidylethanol-amine (PE) and phosphatidylglycerol (PG) exhibit a stepwise increase during the cell cycle. It should be noted that the phase of accumulation of these lipids could shift depending on the duration of the cell cycle. The fall in level of PE was followed by a short-term increase (5-10 min). At the same time the level of cardiolipin was observed to be significantly increased.