Arsenic redox transformation by Pseudomonas sp. HN-2 isolated from arsenic-contaminated soil in Hunan, China

Abstract

A mesophilic, Gram-negative, arsenite[As(III)]-oxidizing and arsenate[As(V)]-reducing bacterial strain, Pseudomonas sp. HN-2, was isolated from an As-contaminated soil. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the strain was closely related to Pseudomonas stutzeri. Under aerobic conditions, this strain oxidized 92.0% (61.4 μmol/L) of arsenite to arsenate within 3 hr of incubation. Reduction of As(V) to As(III) occurred in anoxic conditions. Pseudomonas sp. HN-2 is among the first soil bacteria shown to be capable of both aerobic As(III) oxidation and anoxic As(V) reduction. The strain, as an efficient As(III) oxidizer and As(V) reducer in Pseudomonas, has the potential to impact arsenic mobility in both anoxic and aerobic environments, and has potential application in As remediation processes.

Biologically mediated release of endogenous N2O and NO2 gases in a hydrothermal, hypoxic subterranean environment

“…This behaviour can also be extended to the genera Cupriavidus (Zhang et al, 2009;Estrada-de los Santos et al, 2011), Pseudomonadales (Zhang et al, 2016),…”

Enhanced Arsenic Tolerance in Triticum aestivum Inoculated with Arsenic-Resistant and Plant Growth Promoter Microorganisms from a Heavy Metal-Polluted Soil

“…To cope with the As toxicity, As resistance (ars) genes can be found in the genome of nearly every bacterial species sequenced to date [43], and both, bacteria and fungi have the ability to tolerate As by several mechanisms including valence transformation, extra and intracellular precipitation, active uptake and biosorption [44]. Several studies have shown that the genera Pseudomonas [45,46] can reduce or oxidize arsenic and Tsubouchi and Kaneko [47] showed that Brevundimonas possess the ars operon that allow them to tolerate As by reduction or oxidation, among other processes. In regard to the fungi used in our study, there is no information about how arsenics metabolize.…”

Prospective role of indigenousExiguobacterium profundumPT2 in arsenic biotransformation and biosorption by planktonic cultures and biofilms

“…Many studies have been conducted to explore different ways of transforming or removing As. Such studies have also been widely carried out by using bacteria as many exhibit As resistance, transformation and detoxification (Kao et al 2013;Ghosh et al 2015;Bagade et al 2016;Zhang et al 2016). Few studies have reported arsenic transformation along with biofilm parameters.…”