BIOLOGY OF MODERATELY HALOPHILIC AEROBIC-BACTERIA

The moderately halophilic heterotrophic aerobic bacteria form a divers e group of microorganisms. The property of halophilism is widespread w ithin the bacterial domain. Bacterial halophiles are abundant in envir onments such as salt lakes, saline soils, and salted food products. Mo st species keep their intracellular ionic concentrations at low levels while synthesizing or accumulating organic solutes to provide osmotic equilibrium of the cytoplasm with the surrounding medium. Complex mec hanisms of adjustment of the intracellular environments and the proper ties of the cytoplasmic membrane enable rapid adaptation to changes in the salt concentration of the environment. Approaches to the study of genetic processes have recently been developed for several moderate h alophiles, opening the way toward an understanding of haloadaptation a t the molecular level. The new information obtained is also expected t o contribute to the development of novel biotechnological uses for the se organisms.