Salinity-dependent switching of osmolyte strategies in a moderately halophilic bacterium: glutamate induces proline biosynthesis in Halobacillus halophilus.

ABSTRACT: The moderately halophilic bacterium Halobacillus halophilus copes with the salinity in its environment by the production of compatible solutes. At intermediate salinities of around 1 M NaCl, cells produce glutamate and glutamine in a chloride-dependent manner (S. H. Saum, J. F. Sydow, P. Palm, F. Pfeiffer, D. Oesterhelt, and V. Müller, J. Bacteriol. 188:6808-6815, 2006). Here, we report that H. halophilus switches its osmolyte strategy and produces proline as the dominant solute at higher salinities (2 to 3 M NaCl). The proline biosynthesis genes proH, proJ, and proA were identified. They form a transcriptional unit and encode the pyrroline-5-carboxylate reductase, the glutamate-5-kinase, and the glutamate-5-semialdehyde dehydrogenase, respectively, catalyzing proline biosynthesis from glu

SUBMITTER: Saum SH 

PROVIDER: S-EPMC2045198 | biostudies-literature | 2007 Oct

REPOSITORIES: biostudies-literature