Selenite tolerance and accumulation in the Lactobacillus species

Abstract- The effect of selenium as selenite (Se4+) on cell growth and accumulation in the Lactobacillus species was investigated in batch cultures using Se4+ supplemented MRS broth. All the strains, except two, Lactobacillus rhamnosus LB3 and Lactobacillus fer-mentum LB7, for which a functional role of Se can be suggested, were inhibited by 1 mg l–1 of Se4+. Six tested Lactobacillus strains were able to concentrate selenium, though in different amounts. Most was membrane-bound, and was, in part, bound to-SH groups on the external membrane surface. Selenium was also accumulated in the cytoplasm in both the organic and the elemental form. The isolates were characterised by biochemical reac-tions and 16S rDNA restriction enzyme profiles and different species of Lactobacillus were assigned on the basis of 16S rDNA sequences.