Wang Yize, Sun Xiaoxu, Cao Yubo, Xu Zhimin, Sun Huicai, Guan Xiaojie, Ghani Muhammad Usman, Zheng Lin, Li Baoqin, Huang Duanyi, Sun Weimin
National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, 510650, China.
Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.
Microbiome. 2025 Jun 23;13(1):152. doi: 10.1186/s40168-025-02149-z.
Antimony (Sb) contamination is a serious environmental problem owing to its extensive production worldwide. High concentration of Sb is often detected in mining-contaminated environments, leading to the risk of contamination to the downstream environments through waterflow. Microorganisms play an important role in the fate and transport of Sb. Microbially mediated Sb(V) reduction performs an important environmental service because it can reduce the mobility of Sb and prevent the transport of Sb to downstream. As a commonly found intermediate in mining and aquatic environments, molecular hydrogen (H) may serve as an electron donor to drive Sb(V) reduction, although this biogeochemical process has not yet been reported.
In this study, Sb(V) reduction coupled with H oxidation (HOSbR) was identified in two contrasting Sb-contaminated habitats, i.e., oligotrophic tailings and organic-rich river sediments. DNA-stable isotope probing identified Azospirillum and Hydrogenophaga spp. as the bacteria potentially responsible for HOSbR in oligotrophic tailings and organic-rich river sediments, respectively. Further, Azospirillum spp. were identified as keystone taxa in tailings. The causal inference framework suggested that Azospirillum spp. may contribute to the increased nitrogenase activity in oligotrophic tailings during HOSbR.
These results suggest that bacteria responsible for HOSbR may play various important ecological roles including reducing the mobility of Sb and improving nutrient conditions in oligotrophic habitats. Video Abstract.
由于锑（Sb）在全球范围内的广泛生产，其污染已成为一个严重的环境问题。在受采矿污染的环境中经常检测到高浓度的锑，这导致了通过水流污染下游环境的风险。微生物在锑的归宿和迁移中起着重要作用。微生物介导的锑（V）还原具有重要的环境意义，因为它可以降低锑的迁移性并防止锑向下游传输。作为在采矿和水生环境中常见的中间体，分子氢（H₂）可能作为电子供体驱动锑（V）的还原，尽管这一生物地球化学过程尚未见报道。
在本研究中，在两个形成对比的受锑污染的生境中，即贫营养尾矿和富含有机物的河流沉积物中，鉴定出了与氢气氧化耦合的锑（V）还原（HOSbR）。DNA稳定同位素示踪分别鉴定出固氮螺菌属和嗜氢菌属为贫营养尾矿和富含有机物的河流沉积物中可能负责HOSbR的细菌。此外，固氮螺菌属被确定为尾矿中的关键类群。因果推断框架表明，在HOSbR过程中，固氮螺菌属可能有助于贫营养尾矿中固氮酶活性的增加。
这些结果表明，负责HOSbR的细菌可能发挥各种重要的生态作用，包括降低锑的迁移性和改善贫营养生境中的养分条件。视频摘要。
