Scholarlink

Background <p>ArsR-based whole-cell biosensors offer sensitive colorimetric detection of arsenite [As(III)], yet their broad reactivity toward Group 15 metalloids—especially antimonite [Sb(III)]—limits field specificity. The recently identified <i>ant</i> operon from <i>Comamonas testosteroni</i> JL40 confers Sb(III)-selective resistance via the efflux ATPase AntA, the metallochaperone AntC, and the regulator AntR, providing genetic parts to suppress Sb(III) cross-talk.</p> Results <p>We systematically introduced <i>antA</i>, <i>antC</i>, and three <i>antR</i> homologs into an ArsR regulator coupled with a deoxyviolacein reporter chassis (pJ23119-K12). Co-expression of AntA and AntC under a moderate constitutive promoter (P<i>ceuR</i>) shifted the Sb(III) limit of detection (LOD) from 0.073 µM to 0.586 µM, with a modest increase in the As(III) LOD to 0.018 µM. Subsequent integration of AntR1 not only maintained the As(III) LOD at 0.018 µM but also unexpectedly amplified the As(III) signal, extending the linear range to 36 nM–37.5 µM (R² = 0.991). It suggests that AntR1 may modulate the transcriptional circuitry via cross-regulation, warranting further mechanistic inquiry. The modified biosensor TOP10/pJ23119-antACR1 exhibited high selectivity for As(III) over divalent metals (Cd, Pb, Cu, Hg, Mn, Mg) and tolerated Sb(III) up to 1 µM. Performance was retained in 90% freshwater and 50% seawater matrices, enabling accurate quantification of 0–2.5 µM As(III) in deionized, tap, surface, and marine samples.</p> Conclusion <p>By coupling Sb(III)-specific <i>ant</i> efflux/sequestration components with an ArsR-based sensing module, we developed a portable, low-cost biosensor that overcomes longstanding As(III)/Sb(III) cross-reactivity and performs robustly in complex environmental waters.</p> Graphic abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Repurposing the Sb(III)-specific efflux and sequestration system (ant operon) to mitigate antimonite cross-talk in ArsR-based bacterial arsenite sensors

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年11月24日

查看全文
  • Jingwen Ling,
  • Yan Guo,
  • Mingqi Liu,
  • Jianpei Yun,
  • Boxin Li,
  • Xueqin Yang,
  • Xuli Wu,
  • Chang-ye Hui

摘要

Background

ArsR-based whole-cell biosensors offer sensitive colorimetric detection of arsenite [As(III)], yet their broad reactivity toward Group 15 metalloids—especially antimonite [Sb(III)]—limits field specificity. The recently identified ant operon from Comamonas testosteroni JL40 confers Sb(III)-selective resistance via the efflux ATPase AntA, the metallochaperone AntC, and the regulator AntR, providing genetic parts to suppress Sb(III) cross-talk.

Results

We systematically introduced antA, antC, and three antR homologs into an ArsR regulator coupled with a deoxyviolacein reporter chassis (pJ23119-K12). Co-expression of AntA and AntC under a moderate constitutive promoter (PceuR) shifted the Sb(III) limit of detection (LOD) from 0.073 µM to 0.586 µM, with a modest increase in the As(III) LOD to 0.018 µM. Subsequent integration of AntR1 not only maintained the As(III) LOD at 0.018 µM but also unexpectedly amplified the As(III) signal, extending the linear range to 36 nM–37.5 µM (R² = 0.991). It suggests that AntR1 may modulate the transcriptional circuitry via cross-regulation, warranting further mechanistic inquiry. The modified biosensor TOP10/pJ23119-antACR1 exhibited high selectivity for As(III) over divalent metals (Cd, Pb, Cu, Hg, Mn, Mg) and tolerated Sb(III) up to 1 µM. Performance was retained in 90% freshwater and 50% seawater matrices, enabling accurate quantification of 0–2.5 µM As(III) in deionized, tap, surface, and marine samples.

Conclusion

By coupling Sb(III)-specific ant efflux/sequestration components with an ArsR-based sensing module, we developed a portable, low-cost biosensor that overcomes longstanding As(III)/Sb(III) cross-reactivity and performs robustly in complex environmental waters.

Graphic abstract