Life without air

An early exposure to lipid biochemistry in the laboratory of Konrad Bloch resulted in a fascination with the biosynthesis, structures, and functions of bacterial lipids. The discovery of plasmalogens (1-alk-1'-enyl, 2-acyl phospholipids) in anaerobic Gram-positive bacteria led to studies on the physical chemistry of these lipids and the cellular regulation of membrane lipid polymorphism in bacteria. Later studies in several laboratories showed that the formation of the alk-1-enyl ether bond involves an aerobic process in animal cells and thus is fundamentally different from that in anaerobic organisms. Our work provides evidence for an anaerobic process in which plasmalogens are formed from their corresponding diacyl lipids. Studies on the roles of phospholipases in Listeria monocytogenes revealed distinctions between its phospholipases and those previously discovered in other bacteria and showed how the Listeria enzymes are uniquely fitted to the intracellular lifestyle of this significant human pathogen.