{
  "id": 3905553,
  "title": "Genome-resolved metatranscriptomic analysis of arsenic demethylation and detoxification in a methanogenic rice paddy soil",
  "url": "https://urgent.news/2026/08/27/genome-resolved-metatranscriptomic-analysis-of-arsenic-demethylation",
  "topic": "science",
  "section": "Science",
  "published": "2026-08-27T00:00:00.000Z",
  "source": {
    "name": "bioRxiv",
    "slug": "biorxiv",
    "url": "https://www.biorxiv.org/content/10.64898/2026.08.27.747368v1?rss=1"
  },
  "original_language": "en",
  "account": "Arsenic (As) exists in various forms within rice paddy soils, impacting its toxicity and rice yields. While researchers have studied arsenic methylation processes, the mechanisms of arsenic demethylation in anaerobic conditions, such as flooded rice paddies, remain less understood. To address this knowledge gap, researchers employed genome-resolved metatranscriptomic analysis alongside monitoring of arsenic speciation in methanogenic paddy soil incubations. This approach aimed to uncover microbial pathways involved in arsenic demethylation and assess the influence of toxicity-driven feedbacks on arsenic transformations.\n\nThe experiments revealed that methanogens are responsible for driving anaerobic arsenic demethylation. The addition of trimethylamine, a methylotrophic substrate, expedited arsenic demethylation, although the study found that the increased demethylation was primarily driven by the stimulation of the methanol-specific methyltransferase gene (mtaB), rather than the direct involvement of trimethylamine. Six Methanosarcina metagenome assembled genomes were identified as dominant in methyltransferase gene transcription, with co-transcribed genes involved in multiple arsenic oxidation and efflux pathways. This finding highlights a strong connection between demethylation and detoxification processes at the genomic level.\n\nMoreover, the research demonstrated that higher concentrations of dimethylarsinic acid (DMAs) lead to toxicity-driven feedbacks, inhibiting methanogenesis and subsequently decreasing the pseudo first-order demethylation rate constants. These findings provide valuable insights into the complex interactions between methanogens and (methyl)arsenic species, shedding light on the regulation of arsenic speciation in rice paddy soils.",
  "summary": "Microbial methylation and demethylation of arsenic (As) in rice paddy soils influence the speciation and toxicity of As in rice, with implications for human health and rice yields. While there has been substantial progress in characterizing microbial communities involved in As methylation, the mechanisms and microbial drivers of As demethylation remain comparatively less resolved, particularly in…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}