The biosynthesis of cardiolipin (CL) in bacteria begins in the cytoplasm. Dihydroxyacetone phosphate is reduced by glycerol-3-phosphate dehydrogenase to form glycerol 3-phosphate, using NADH as a cofactor. Glycerol 3-phosphate then reacts with an acyl-CoA via glycerol-3-phosphate acyltransferase, producing 1-acyl-sn-glycerol-3-phosphate (lysophosphatidic acid, LysoPA). The resulting LysoPA undergoes acylation by 1-acylglycerol-3-phosphate O-acyltransferase, forming phosphatidic acid (PA). PA reacts with cytidine triphosphate (CTP) in a reaction catalyzed by phosphatidate cytidylyltransferase, yielding CDP-diacylglycerol (CDP-DG). CDP-DG is converted to phosphatidylglycerophosphate (PGP) by CDP-diacylglycerol–glycerol-3-phosphate 3-phosphatidyltransferase, and PGP is then dephosphorylated by phosphatidylglycerophosphatase to produce phosphatidylglycerol (PG). CL is formed when PG reacts with another CDP-DG molecule under the action of cardiolipin synthase, producing CL and releasing cytidine monophosphate. Bacterial cardiolipin remodeling begins with the removal of an acyl chain from CL by a cardiolipin-specific phospholipase, producing 1-monolysocardiolipin (MLCL). The acyl chain is then reintroduced by a lysophosphatidylcholine acyltransferase (or similar bacterial acyltransferase), transferring an acyl group from a phospholipid donor (e.g., phosphatidylcholine) to MLCL, regenerating mature cardiolipin.

Cardiolipin Biosynthesis via MLCL(0:0/10:0/18:1(9Z)/22:1(11Z)) References