The objective of this research project is to find means to facilitate the study of the biogenesis of bacterial membranes and to use these means to elucidate mechanisms for the formation of membranes and regulatory functions dependent upon or affecting membrane systems. We have previously isolated mutants in four genera of bacteria that enable us to reversibly stop lipid synthesis. Using these mutants we will investigate the integration into membrane of complex systems such as those for electron transport and photosynthesis. The physiological consequences of stopping lipid synthesis will also be investigated. We will study the role of lipid synthesis in cell division by constructing strains that have mutations that allow manipulation of lipid synthesis and that are also conditionally defective in cell division. We hope to determine whether lipid synthesis is required during the actual division process or whether previously synthesized material can be utilized. If the latter is true, we also hope to classify mutants that are conditional for division according to their ability to accumulate membrane lipid, when prevented from dividing, in a form usable for division.