Anionic phospholipids have been shown to interact with both membrane-associated proteins and integral membrane proteins. The objective of this work was to determine whether bacteriolysis induced by treatment with ampicillin was influenced by the levels of anionic membrane phospholipids in Escherichia coli strain HDL11. The pgsA gene, encoding phosphatidylglycerophosphate synthase, in HDL11 is under the control of lacOP, and the levels of anionic membrane phospholipids are consequently dependent on IPTG. The results indicate that limiting the amounts of phosphatidylglycerol and cardiolipin did not affect the lysis process in both growing and nongrowing bacteria.