conclusion mature biofilms were found to be much more resistant to antifungal agents and the host immune system than free cells. the factors responsible for high resistance included the complex architecture of biofilms, ecm, increased expression of drug efflux pumps, and metabolic plasticity. objectives the present work investigated certain aspects of the resistance of c. albicans biofilms to d...

An arsenite-oxidizing Hydrogenobaculum strain was isolated from a geothermal spring in Yellowstone National Park, Wyo., that was previously shown to contain microbial populations engaged in arsenite oxidation. The isolate was sensitive to both arsenite and arsenate and behaved as an obligate chemolithoautotroph that used H(2) as its sole energy source and had an optimum temperature of 55 to 60 ...

BACKGROUND The purpose of this study was to identify arsenite-oxidizing halobacteria in samples obtained from Salar de Punta Negra, II Region of Chile. Seven bacterial isolates, numbered as isolates I to VII, grown in a culture medium with 100 ppm as NaAsO2 (As (III)) were tested. Bacterial growth kinetics and the percent of arsenite removal (PAR) were performed simultaneously with the detectio...

The title compounds contain the catena-arsenite [AsO(2)](n)(n-) unit, in which the As(III) atom is pyramidally coordinated to one terminal and two bridging O atoms, resulting in an infinite anionic chain. Ethylenediammonium catena-arsenite, (C(2)H(10)N(2))(0.5)[AsO(2)], is the first example of this anion in the company of an organic cation. The ethylenediammonium species interact with the [AsO(...

Novel arsenite [As(III)] oxidase structural genes (aoxAB) were cloned from Hydrogenobaculum bacteria isolated from an acidic geothermal spring. Reverse transcriptase PCR demonstrated expression throughout the outflow channel, and the aoxB cDNA clones exhibited distribution patterns relative to the physicochemical gradients in the spring. Microelectrode analyses provided evidence of quantitative...

A method for the measurement of subnanogram quantities of iodine is describeo. Procedural detail and precision of results are presented for application of the method to protein-bound or total iodine in duplicate on 12.3 ii.l serum. Following wet ashing with chloric reagent, the iodine-catalyzed cerate-arsenite reaction was carried out at temperatures between 23 and 27#{176}, and the reaction ra...

Speciation is a key determinant in the toxicity, behavior, and fate of arsenic (As) in the environment. However, little is known about the transformation of As species mediated by floating macrophytes and the phyllosphere bacteria in aquatic and wetland environment. In this study, Wolffia australiana, a rootless floating duckweed, was cultured with (W+B) or without (W-B) phyllosphere bacteria t...

Previous studies in an acid-sulfate-chloride spring in Yellowstone National Park found that microbial arsenite [As(III)] oxidation is absent in regions of the spring outflow channel where H(2)S exceeds approximately 5 microM and served as a backdrop for continued efforts in the present study. Ex situ assays with microbial mat samples demonstrated immediate As(III) oxidation activity when H(2)S ...

Acidovorax sp. strain NO1, isolated from gold mine soil, was shown to be a facultative anaerobic arsenite-oxidizing and nitrate-reducing bacterium. The reported draft genome predicts the presence of genes involved in arsenic metabolism, nitrate reduction, phosphate transport, and multiple metal resistances and indicates putative horizontal gene transfer events.