Detoxification of ars genotypes by arsenite-oxidizing bacteria through arsenic biotransformation.

The detoxification process of transforming arsenite (As(III)) to arsenate (As(V)) through bacterial oxidation presents a potent approach for bioremediation of arsenic-polluted soils in abandoned mines. In this study, twelve indigenous arsenic-oxidizing bacteria (AOB) were isolated from arsenic-contaminated soils. Among these, Paenibacillus xylanexedens EBC-SK As2 (MF928871) and Ochrobactrum anthropi EBC-SK As11 (MF928880) were identified as the most effective arsenic-oxidizing isolates.

Arsenic biotransformation potential of microbial arsH responses in the biogeochemical cycling of arsenic-contaminated groundwater.

ArsH encodes an oxidoreductase, an NAD(P)H-dependent mononucleotide reductase, with an unknown function, frequently within an ars operon, and is widely distributed in bacteria. Novel arsenite-oxidizing bacteria have been isolated from arsenic-contaminated groundwater and surface soil in Vietnam. We found that ArsH gene activity, with arsenite oxidase in the periplasm; it revealed arsenic oxidation potential of the arsH system.

RACK1 depletion in the ribosome induces selective translation for non-canonical autophagy.

RACK1, which was first demonstrated as a substrate of PKCβ II, functions as a scaffold protein and associates with the 40S small ribosomal subunit. According to previous reports, ribosomal RACK1 was also suggested to control translation depending on the status in translating ribosome. We here show that RACK1 knockdown induces autophagy independent of upstream canonical factors such as Beclin1, Atg7 and Atg5/12 conjugates.

Meta-Analysis of Prognostic Implications of Exercise-Induced Ventricular Premature Complexes in the General Population.

Ventricular premature complexes (VPCs) during stress testing in the general population are commonly seen in clinical practice, but their prognostic value is not well understood. A comprehensive literature search of MEDLINE, Embase, and the Cochrane Library from January 1970 to May 2015 was conducted. Observational cohort studies on general populations evaluating the association between exercise-induced VPCs and all-cause or cardiovascular mortality were included in the analysis.

Biotransformation of arsenite and bacterial aox activity in drinking water produced from surface water of floating houses: Arsenic contamination in Cambodia.

The potential arsenite bioteansformation activity of arsenic was investigated by examining bacterial arsenic arsenite-oxidizing gene such as aoxS, aoxR, aoxA, aoxB, aoxC, and aoxD in high arsenic-contaminated drinking water produced from the surface water of floating houses. There is a biogeochemical cycle of activity involving arsenite oxidase aox system and the ars (arsenic resistance system) gene operon and aoxR leader gene activity in Alcaligenes faecalis SRR-11 and aoxS leader gene activity in Achromobacter xylosoxidans TSL-66. Batch experiments showed that SRR-11 and TSL-66 completely oxidized 1 mM of As (III) to As (V) within 35-40 h.

Ribosomal protein S3 localizes on the mitotic spindle and functions as a microtubule associated protein in mitosis.

The human ribosomal protein S3 (rpS3) has multi-functions such as translation, DNA repair and apoptosis. These multiple functions are regulated by post-translational modifications including phosphorylation, methylation and sumoylation. We report here a novel function of rpS3 that is involved in mitosis.

Bacterial aox genotype from arsenic contaminated mine to adjacent coastal sediment: evidences for potential biogeochemical arsenic oxidation.

The potential biogeochemical redox activity of arsenic was investigated by examining bacterial arsenic (As) redox genes such as aox, ars, and arr in arsenic-contaminated abandoned mine area and adjacent coastal sediments. Consistent with aerobic sediment and water samples from the mine through coastal areas, bacterial genes involing arsenic(V) (arsenate, AsO(4)(3-)) reduction such as arsC and arrA were identified only in a few samples, where's bacterial aoxB gene encoding arsenite oxidase which is a central role in arsenic(III) (AsO(2)(-)) oxidation of aox operon. This study suggests that evaluation of arsenite-oxidizing bacteria including aox genotype may lead to a better understanding of molecular geomicrobiology in arsenic biogeochemistry, which can be applied to the bioremediation of arsenic contaminated mines along the coast of Gwangyang Bay.

Effects of pH and dissolved oxygen on Cr(VI) removal in Fe(0)/H2O systems.

The effects of pH and dissolved oxygen (DO) on aqueous Cr(VI) removal by micro-scale zero-valent iron (Fe(0)/H(2)O system) were investigated. Batch experiments were conducted at pH 4.0, 5.

Arsenic detoxification potential of aox genes in arsenite-oxidizing bacteria isolated from natural and constructed wetlands in the Republic of Korea.

Arsenic is subject to microbial interactions, which support a wide range of biogeochemical transformations of elements in natural environments such as wetlands. The arsenic detoxification potential of the bacterial strains was investigated with the arsenite oxidation gene, aox genotype, which were isolated from the natural and constructed wetlands. The isolates were able to grow in the presence of 10 mM of sodium arsenite (As(III) as NaAsO(2)) and 1 mM of D: +glucose.

Effect of arsenic on p53 mutation and occurrence of teratogenic salamanders: their potential as ecological indicators for arsenic contamination.

The p53 mutation in salamanders can be used as an indicator of arsenic contamination. The influence of arsenic exposure was studied on mutation of tumor suppressor gene in salamanders collected from several As-contaminated mine areas in Korea. Salamander eggs and larvae were exposed to arsenic in a toxicity test, and teratogenic salamanders found in heavy metal- and As-contaminated water from As-Bi mines were evaluated using PCR-SSCP to determine if they would be useful as an ecological indicator species.

Biogeochemical cyclic activity of bacterial arsB in arsenic-contaminated mines.

Biogeochemical cyclic activity of the ars (arsenic resistance system) operon is arsB influx/efflux encoded by the ecological of Pseudomonas putida. This suggests that studying arsenite-oxidizing bacteria may lead to a better understanding of molecular geomicrobiology, which can be applied to the bioremediation of arsenic-contaminated mines. This is the first report in which multiple arsB-binding mechanisms have been used on indigenous bacteria.

Arsenite oxidation by Alcaligenes sp. strain RS-19 isolated from arsenic-contaminated mines in the Republic of Korea.

Arsenite [As(III)]-oxidizing bacteria play important roles in reducing arsenic [As] toxicity and mobility in As-contaminated areas. As-resistant bacteria were isolated from the soils of two abandoned mines in the Republic of Korea. The isolated bacteria showed relatively high resistances to As(III) up to 26 mM.

The ars genotype characterization of arsenic-resistant bacteria from arsenic-contaminated gold-silver mines in the Republic of Korea.

The isolates were identified on the basis of ars genotype characteristics as well as arsenic oxidation/reduction analysis based on the molecular detection characterization. Diversity, pH range (4.0 to 7.

Isolation and ars detoxification of arsenite-oxidizing bacteria from abandoned arsenic-contaminated mines.

The ecosystems of certain abandoned mines contain arsenic-resistant bacteria capable of performing detoxification when an ars gene is present in the bacterial genome. The ars gene has already been isolated from Pseudomonas putida and identified as a member of the membrane transport regulatory deoxyribonucleic acid family. The arsenite-oxidizing bacterial strains isolated in the present study were found to grow in the presence of 66.

The interaction of an antimicrobial decapeptide with phospholipid vesicles.

Previously, by using combinatorial peptide libraries, we have identified activity-optimized decapeptide (KSL, KKVVFKVKFK-NH(2)), which exhibited a broad spectrum of the activity against bacteria and fungi without hemolytic activity. In order to examine lipid requirements and to understand the mode of KSL action, we investigated interactions of the peptide with vesicles consisting of various lipid compositions. KSL increased the permeability of negatively charged but not zwitterionic phospholipid membranes, and the leakage was independent on the size of encapsulated molecules (calcein, 1-aminonaphthalene-3,6,8-trisulfonic acid (ANTS)/N,N'-p-xylene bis(pyridinium) bromide (DPX), and fluorescein isothiocyanate (FITC)-dextran with different molecular weight), indicating that the peptide did not form pores or channels in this leakage process.

Isolation and identification of thiocyanate utilizing chemolithotrophs from gold mine soils.

A mixed bacterial culture capable of growing in potassium-thiocyanate containing medium (200 mg KSCN) has been isolated from bacterial suspensions of soil samples collected near gold mines in Kumjung (Korea). The isolates were initially characterized by metabolic profile analysis and were identified as Bacillus thermoglucosidasius, Bacillus cereus, Bacillus licheniformis, Bacillus mycoides, Brevibacterium epidermidis, Brevibacterium otitidis, and Corynebacterium nitrilophilus. One of the seven isolates was initially characterized as Brevibacterium epidermidis, which is not known to degrade thiocyanate.