Isolation and characterization of arsenite-oxidizing bacteria from arsenic-contaminated soils in Thailand

Abstract

Two hundred and eighty-eight arsenic-resistant bacteria were isolated by an enrichment culture method from a total of 69 arsenic-contaminated soil-samples collected from Dantchaeng district in Suphanburi province (47 samples), and from Ron Phiboon district in Nakhon Sri Thammarat province (22 samples), in Central and Southern Thailand, respectively. Twenty-four of the 288 isolated arsenic-resistant bacteria were found to be arsenite-oxidizing bacteria. On the basis of their morphological, cultural, physiological, biochemical and chemotaxonomic characteristics, and supported by phylogenetic analysis based upon their 16S rRNA gene sequences, they were divided into five groups, within the genera Acinetobacter, Flavobacterium, Pseudomonas, Sinorhizobium and Sphingomonas, respectively. Within genera, phylogenetic analysis using the 16S rRNA gene sequences suggested that they were comprised of at least ten species, five isolates being closely related to known bacteria (Acinetobacter calcoaceticus NCCB 22016 T , Pseudomonas plecoglossicida FPC951 T , Ps. knackmussii B13 T , Sinorhizobium morelense Lc04 T , and Sphingomonas subterranea IFO16086 T ). The other five proposed species are likely to be new species closely related to Flavobacterium johnsoniae, Sinorhizobium morelense, Acinetobacter calcoaceticus and Pseudomonas plecoglossicida, but this awaits further characterization for confirmation of the taxonomic status. No overlap in isolated species or strains was observed between the two sites. The strain distribution and characterization are described.

Microbial community response to environmental changes in a technosol historically contaminated by the burning of chemical ammunitions

“…The main genus, Sphingomonas, comprises some heterotrophic species commonly found on contaminated sites, including sites polluted by metals (Beattie et al, 2018). They are able to degrade aromatic compounds (Fredrickson et al, 1995 ;Zylstra and Kim, 1997) and carry functional genes, such as the ars genes, linked to As resistance (Macur et al, 2001 ;Escalante et al, 2009) and the aioA genes linked to As oxidation (Kinegam et al, 2008). Other major heterotrophic genera, such as Pseudolabrys and Bryobacter, may contribute to the degradation of organic molecules initially present or provided with the organic litter during the mesocosm experiment.…”

Characteristics of Bacterial Community and Function in Paddy Soil Profile around Antimony Mine and Its Response to Antimony and Arsenic Contamination

“…Through symbiotic network analysis, we found that Anaeromyxobacter (genus11) had a negative correlation with arsenate reductase (arsC, arsC1, and arsC2), which further confirmed that Astot has a negative impact on Proteobacteria. Geobacter [62], and Sphingomonas [63] were typical As metabolic bacteria. Sphingomonas had a positive response to As contamination fractions but had no response to Sb contamination fractions.…”

Isolation of Arsenic Resistant Escherichia coli from Sewage Water and Its Potential in Arsenic Biotransformation

“…Screening for As (III) oxidation and As (V) reduction activity The bacteria were tested on the ability to oxidize As (III) or reduce As (V) using a qualitative AgNO 3 screening method [10,11]. The bacteria were grown on nutrient broth with either 129.91 mg/L NaAsO 2 (sodium arsenite) or 312.01 mg/L Na 2 HAsO 4 (sodium arsenate).…”

“…E. coli grow at 0.01 mM mercury concentration (a), 1 mM zinc concentration (b), and 1 mM nickel (c). Screening for As (III) oxidation and As (V) reduction activity The bacteria were tested on the ability to oxidize As (III) or reduce As (V) using a qualitative AgNO 3 screening method [10,11]. A light yellow color in mixtures containing arsenate indicates positive arsenate oxidation reaction (oxidation of the arsenate in the mixture to arsenite).…”

“…This means that the arsenate supplied was transformed into arsenite. Although absence of any brown coloring shows that arsenite was not transformed to arsenate [10,11].…”