Phosphatidylinositol cannot substitute for phosphatidylglycerol in supporting cell growth of Escherichia coli

Escherichia coli cells are dependent on the anionic phospholipid phosphatidylglycerol for cell growth. Introduction into cells of the ability to make phosphatidylinositol did not suppress the need for naturally occurring phosphatidylglycerol. Therefore, the requirement for phosphatidylglycerol must be more than maintenance of the proper membrane surface charge.