Biochemical and molecular characterization of the biosynthesis of glutamine and glutamate, two major compatible solutes in the moderately halophilic bacterium Halobacillus halophilus.

ABSTRACT: The moderately halophilic, chloride-dependent bacterium Halobacillus halophilus produces glutamate and glutamine as main compatible solutes at external salinities of 1.0 to 1.5 M NaCl. The routes for the biosynthesis of these solutes and their regulation were examined. The genome contains two genes potentially encoding glutamate dehydrogenases and two genes for the small subunit of a glutamate synthase, but only one gene for the large subunit. However, the expression of these genes was not salt dependent, nor were the corresponding enzymatic activities detectable in cell extracts of cells grown at different salinities. In contrast, glutamine synthetase activity was readily detectable in H. halophilus. Induction of glutamine synthetase activity was strictly salt dependent and reached a maxi

SUBMITTER: Saum SH 

PROVIDER: S-EPMC1595520 | biostudies-literature | 2006 Oct

REPOSITORIES: biostudies-literature