ArsM-mediated arsenite volatilization is limited by efflux catalyzed by As efflux transporters

Yang, Pengmin; Ke, Changdong; Zhao, Chungui; Kuang, Qingyue; Liu, Bixiu; Xue, Xudong; Rensing, Christopher; Yang, Suping

doi:10.1016/j.chemosphere.2019.124822

Cited by 10 publications

(4 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Further supporting this finding, As(III) efflux has been found to be the limiting factor for As volatilization in recombinant E. coli strains coexpressing arsB / acr3 and arsM genes …”

Section: Resultsmentioning

confidence: 99%

“…Further supporting this finding, As(III) efflux has been found to be the limiting factor for As volatilization in recombinant E. coli strains coexpressing arsB/acr3 and arsM genes. 58 Multiple Roles for Arsenic Methylation in Aerobes versus Anaerobes. It is apparent that, in the case of aerobic strains, ArsM plays a role in the detoxification of inorganic As.…”

Section: Environmental Science and Technologymentioning

confidence: 99%

See 1 more Smart Citation

Variability in Arsenic Methylation Efficiency across Aerobic and Anaerobic Microorganisms

Viacava

Meibom

Ortega

et al. 2020

Environ. Sci. Technol.

View full text Add to dashboard Cite

Microbially-mediated methylation of arsenic (As) plays an important role in the As biogeochemical cycle, particularly in rice paddy soils where methylated As, generated microbially, is translocated into rice grains. The presence of the arsenite (As(III)) methyltransferase gene (arsM) in soil microbes has been used as an indication of their capacity for As methylation. Here, we evaluate the ability of seven microorganisms encoding active ArsM enzymes to methylate As. Amongst those, only the aerobic species were efficient methylators. The anaerobic microorganisms presented high resistance to As exposure, presumably through their efficient As(III) efflux, but methylated As poorly. The only exception were methanogens, for which efficient As methylation was seemingly an artifact of membrane disruption. Deletion of an efflux pump gene (acr3) in one of the anaerobes, Clostridium pasteurianum, rendered the strain sensitive to As and capable of more efficiently methylating As. Our results led to the following conclusions: (i) encoding a functional ArsM enzyme does not guarantee that a microorganism will actively drive As methylation in the presence of the metalloid and (ii) there is an inverse relationship between efficient microbial As efflux and its methylation, because the former prevents the intracellular accumulation of As.

show abstract

“…Further supporting this finding, As(III) efflux has been found to be the limiting factor for As volatilization in recombinant E. coli strains coexpressing arsB / acr3 and arsM genes …”

Section: Resultsmentioning

confidence: 99%

Section: Environmental Science and Technologymentioning

confidence: 99%

Variability in Arsenic Methylation Efficiency across Aerobic and Anaerobic Microorganisms

Viacava

Meibom

Ortega

et al. 2020

Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…For Desulfotomaculum , not only arsM but also arsB and arsR were transcribed (Table S10). In view that ArsB is capable of extruding arsenite from the cell, Desulfotomaculum containing transcribed arsB genes contributed little to the arsenic methylation possibly because of a lack of arsenite to be methylated in vivo. , Likewise, arsM and acr 3/ arsB -carrying anaerobic bacteria, including Clostridium pasteurianum, Geobacter metallireducens GS-15, and Anaeromusa acidaminophila, were reported to exhibit negligible arsenic methylation efficiency as well Clostridium pasteurianum with a knockout of the acr 3 gene greatly improved intracellular arsenic accumulation, arsM expression, and arsenic methylation, proving that efficient arsenite efflux did preclude arsenic methylation .…”

Section: Discussionmentioning

confidence: 99%

Methanogens-Driven Arsenic Methylation Preceding Formation of Methylated Thioarsenates in Sulfide-Rich Hot Springs

Wang

Guo

et al. 2023

Environ. Sci. Technol.

View full text Add to dashboard Cite

Hot springs represent a major source of arsenic release into the environment. Speciation is typically reported to be dominated by arsenite, arsenate, and inorganic thiolated arsenates. Much less is known about the relevance and formation of methylated thioarsenates, a group with species of high mobility and toxicity. In hot spring samples taken from the Tengchong volcanic region in China, methylated thioarsenates contributed up to 13% to total arsenic. Enrichment cultures were obtained from the corresponding sediment samples and incubated to assess their capability to convert arsenite into methylated thioarsenates over time and in the presence of different microbial inhibitors. In contrast to observations in other environmental systems (e.g., paddy soils), there was no solid evidence, supporting that the sulfate-reducing bacteria contributed to the arsenic methylation. Methanosarcina, the sole genus of methanogens detected in the enrichment cultures, as well as Methanosarcina thermophila TM-1, a pure strain within the genus, did methylate arsenic. We propose that methylated thioarsenates in a typical sulfide-rich hot spring environment like Tengchong form via a combination of biotic arsenic methylation driven by thermophilic methanogens and arsenic thiolation with either geogenic sulfide or sulfide produced by sulfate-reducing bacteria.

show abstract

“…If that is confirmed, it is conceivable that As methylation may not occur in pure cultures but only in microbial communities, triggered by metabolites produced by the microbiota. Alternatively, arsM -harbouring microorganisms that express As(III) efflux pump(s), the major pathway of As resistance within bacteria [ 20 ], may not methylate As due to the efficient removal of As(III) from the cytoplasm, which is the location of ArsM [ 21 , 22 ]. This effect could be direct, i.e., insufficient substrate concentration, or indirect, i.e., the intracellular As(III) concentration is too low to induce arsM expression.…”

Section: Introductionmentioning

confidence: 99%

Meta-omics-aided isolation of an elusive anaerobic arsenic-methylating soil bacterium

et al. 2022

View full text Add to dashboard Cite

Soil microbiomes harbour unparalleled functional and phylogenetic diversity. However, extracting isolates with a targeted function from complex microbiomes is not straightforward, particularly if the associated phenotype does not lend itself to high-throughput screening. Here, we tackle the methylation of arsenic (As) in anoxic soils. As methylation was proposed to be catalysed by sulfate-reducing bacteria. However, to date, there are no available anaerobic isolates capable of As methylation, whether sulfate-reducing or otherwise. The isolation of such a microorganism has been thwarted by the fact that the anaerobic bacteria harbouring a functional arsenite S-adenosylmethionine methyltransferase (ArsM) tested to date did not methylate As in pure culture. Additionally, fortuitous As methylation can result from the release of non-specific methyltransferases upon lysis. Thus, we combined metagenomics, metatranscriptomics, and metaproteomics to identify the microorganisms actively methylating As in anoxic soil-derived microbial cultures. Based on the metagenome-assembled genomes of microorganisms expressing ArsM, we isolated Paraclostridium sp. strain EML, which was confirmed to actively methylate As anaerobically. This work is an example of the application of meta-omics to the isolation of elusive microorganisms.

show abstract

ArsM-mediated arsenite volatilization is limited by efflux catalyzed by As efflux transporters

Cited by 10 publications

References 54 publications

Variability in Arsenic Methylation Efficiency across Aerobic and Anaerobic Microorganisms

Variability in Arsenic Methylation Efficiency across Aerobic and Anaerobic Microorganisms

Methanogens-Driven Arsenic Methylation Preceding Formation of Methylated Thioarsenates in Sulfide-Rich Hot Springs

Meta-omics-aided isolation of an elusive anaerobic arsenic-methylating soil bacterium

Contact Info

Product

Resources

About