Effects of bacteriophage M13 infection upon phospholipid and fatty acid compositions of Escherichia coli.

Escherichia coli K38 were grown and infected with wild type and amber mutants of bacteriophage M13 in the early log phase. Lipid compositions of the infected and healthy cultures, grown under identical conditions, were determined 2 hr after infection. From the results, it was observed that total lipid and total phospholipid content remained nearly constant, suggesting that the cell membrane which contained the maximum phospholipids was not damaged by the infection. Moreover, the percentage of diphosphatidylglycerol and lyso- compounds corresponding to phosphatidylethanolamine and phosphatidylglycerol increased, while phosphatidylethanolamine and phosphatidylglycerol decreased. The increase in lyso- compounds may be due to the relase of phospholipase A2 (a periplasmic enzyme) from the cell wall after damage by the infection. Bacteriophage M13 infection had no effect on the fatty acid compostion of the phospholipids.