The bacterial metallome: composition and stability with specific reference to the anaerobic bacterium Desulfovibrio desulfuricans.

In bacteria, the intracellular metal content or metallome reflects the metabolic requirements of the cell. When comparing the composition of metals in phytoplankton and bacteria that make up the macronutrients and the trace elements, we have determined that the content of trace elements in both of these microorganisms is markedly similar. The trace metals consisting of transition metals plus zinc are present in a stoichometric molar formula that we have calculated to be as follows: Fe(1)Mn(0.

Arsenate detoxification in a Pseudomonad hypertolerant to arsenic.

Pseudomonas sp. strain As-1, obtained from an electroplating industrial effluent, was capable of growing aerobically in growth medium supplemented with up to 65 mM arsenate (As (V)), significantly higher concentrations than those tolerated by other reference arsenic resistant bacteria. The majority of the arsenic was detected in culture supernatants as arsenite (As (III)) and X-ray absorbance spectroscopy suggested that 30% of this cell-bound arsenic was As (V), 65% As (III) and 5% of arsenic was associated with sulphur.

Cr(VI) detoxification by Desulfovibrio vulgaris strain Hildenborough: microbe-metal interactions studies.

Toxic heavy metals constitute a worldwide environmental pollution problem. Bioremediation technologies represent efficient alternatives to the classic cleaning-up of contaminated soil and ground water. Most toxic heavy metals such as chromium are less soluble and toxic when reduced than when oxidized.

Functional refolding of the Campylobacter jejuni MOMP (major outer membrane protein) porin by GroEL from the same species.

Functional and structural studies of outer membrane proteins from Gram-negative bacteria are frequently carried out using refolded proteins. Recombinant proteins are produced in Escherichia coli as inclusion bodies and then tediously refolded by dilution in buffered detergent solutions. In the present work, we obtained the refolding of MOMP (major outer membrane protein) from Campylobacter assisted by the molecular chaperone GroEL.

Oral microbial heat-shock proteins and their potential contributions to infections.

The oral cavity is a complex ecosystem in which several hundred microbial species normally cohabit harmoniously. However, under certain special conditions, the growth of some micro-organisms with a pathogenic potential is promoted, leading to infections such as dental caries, periodontal disease, and stomatitis. The physiology and pathogenic properties of micro-organisms are influenced by modifications in environmental conditions that lead to the synthesis of specific proteins known as the heat-shock proteins (HSPs).

Stress response in Actinobacillus actinomycetemcomitans: induction of general and specific stress proteins.

Stress proteins are highly conserved proteins that are essential for cell survival. In this study, the induction of general and specific stress proteins in Actinobacillus actinomycetemcomitans cells subjected to different stress conditions was evaluated by two-dimensional SDS-PAGE analysis. Twenty-eight (up- or down)regulated proteins, including DnaK and GroEL proteins, were identified as general stress proteins.