Aerotolerant Thiosulfate-Reducing Bacterium sp. Strain WBS Isolated from Littoral Bottom Sediments of the White Sea-Biochemical and Genome Analysis.

The strain WBS, an anaerobic, psychro- and halotolerant bacterium belonging to the genus , was isolated from the littoral bottom sediments of the White Sea, Arctic, Russia. WBS grew at temperatures between 8 and 32 °C (optimum growth at 18-20 °C), pH between 5.2 and 8.

Phylogenetic diversity in sulphate-reducing bacterial communities from oxidised and reduced bottom sediments of the Barents Sea.

In the bottom sediments from a number of the Barents Sea sites, including coastal areas of the Novaya Zemlya, Franz Josef Land, and Svalbard archipelagos, sulphate reduction rates were measured and the phylogenetic composition of sulphate-reducing bacterial (SRB) communities was analysed for the first time. Molecular genetic analysis of the sequences of the 16S rRNA and dsrB genes (the latter encodes the β-subunit of dissimilatory (bi)sulphite reductase) revealed significant differences in the composition of bacterial communities in different sampling stations and sediment horizons of the Barents Sea depending on the physicochemical conditions. The major bacteria involved in reduction of sulphur compounds in Arctic marine bottom sediments belonged to Desulfobulbaceae, Desulfobacteraceae, Desulfovibrionaceae, Desulfuromonadaceae, and Desulfarculaceae families, as well as to uncultured clades SAR324 and Sva0485.

In Vitro Evaluation of Probiotic Potential of Selected Lactic Acid Bacteria Strains.

Research of human microbiome demonstrates that in order to develop next generation of probiotic agents, it is necessary to choose bacterial strains featured by special properties, such as the ability of the cells to attach to intestinal walls, resistance to bile and acids, bacteriocin synthesis, antioxidative and antipathogenic activity, and survivability in intestines. Thirty-three strains of lactic acid bacteria of Lactobacillus and Lactococcus genera from the Lomonosov Moscow State University Collection of Microorganisms (CM MSU) have been tested for important probiotic properties which assist these bacteria to settle effectively in intestines: cell adhesion, ability to form biofilms, agglutination with lectin (concanavalin A), and antimicrobial activity. The results of experiments clearly demonstrate that all these properties can be classified as strain characteristics and differ even within the same species.

The positive effect of exogenous hemin on a resistance of strict anaerobic archaeon Methanobrevibacter arboriphilus to oxidative stresses.

Methanogenic archaeon Methanobrevibacter arboriphilus (strains AZ and DH1), which is a strict anaerobic microorganism not able to synthesize heme, possessed a very high catalase activity in the presence of 20-50 μM hemin in a growth medium. We investigated the effect of various oxidative stresses (hydrogen peroxide and oxygenation) on M. arboriphilus cells grown on the standard nutrient medium supplemented with 0.

Response of Desulfovibrio vulgaris Hildenborough to hydrogen peroxide: enzymatic and transcriptional analyses.

We studied the effect of hydrogen peroxide (H(2)O(2)) stress on the anaerobic sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough. In a lactate/sulfate medium, growth was affected from 0.1 mM H(2)O(2) and totally inhibited at 0.

Antimicrobial activity of different proteins and their fragments from Bacillus thuringiensis parasporal crystals against clostridia and archaea.

Proteins of parasporal crystals (Cry proteins) from entomopathogenic bacterium Bacillus thuringiensis (subspecies kurstaki, galleriae, tenebrionis) as well as some fragments of these proteins, obtained by limited proteolysis, are capable of antimicrobial action against anaerobic bacteria and archaea-Clostridium butyricum, Clostridium acetobutylicum and Methanosarcina barkeri. The MICs are 45-150 microg/mL. Electron microscopy showed that lysis of M.

The catalase and superoxide dismutase genes are transcriptionally up-regulated upon oxidative stress in the strictly anaerobic archaeon Methanosarcina barkeri.

Methanosarcina barkeri is a strictly anaerobic methanogenic archaeon, which can survive oxidative stress. The oxidative stress agent paraquat (PQ) suppressed growth of M. barkeri at concentrations of 50-200 microM.