Active increase in cardiolipin synthesis in the stationary growth phase and its physiological significance in Escherichia coli

Abstract

Activity of the Escherichia coli cardiolipin synthase, encoded by cls, increased about 10-fold in the stationary growth phase, while other committedstep enzymes in phospholipid biosynthesis rather decreased. A null cls mutant lost viability to 10⁻⁴ of the wild-type cells during the prolonged incubation for 5 days. Cardiolipin was most stable among membrane phospholipids during the incubation. Accordingly, cardiolipin should play a role in survival of the cell and E. coli employs a sophisticated way to form cardiolipin according to need even under non-growing conditions.