硫酸盐的减少驱动高甲基的形成,在水柱的温和的淡水湖的水柱
Benjamin D Peterson1,2,3,4, Sarah E Janssen5, Brett A Poulin4
1School of Freshwater Sciences, University of Wisconsin─Milwaukee, Milwaukee, Wisconsin 53204, United States.
Environmental science & technology
|March 28, 2025
概括
环死湖中的甲基 (MeHg) 生产主要是由具有hgcAB基因的硫酸盐减少细菌驱动的. 了解这些微生物过程是控制水生生态系统中污染的关键.
科学领域:
- 环境微生物学 环境微生物学
- 生物地质化学生物地质化学
- 水生毒理学 水生毒理学
背景情况:
- 甲基 (MeHg) 是水生食物网中的有毒和生物累积污染物.
- 微生物 (Hg) 通过hgcAB基因的甲基化是一个关键的过程,但其调节和环境驱动因素的理解很少,特别是在安抚性系统中.
研究的目的:
- 研究微生物和生态化学因素控制甲基化和MeHg积累在温和的淡水湖.
- 为了确定甲基化与脱甲基化过程对MeHg度的相对重要性.
主要方法:
- 量化Hg甲基化和MeHg脱甲基化率.
- 测量了周围环境的MeHg度.
- 评估了hgcA基因的丰度和表达.
- 使用酸盐处理来抑制硫酸盐的减少.
- 分析了与hgcA相关的微生物社区组成.
主要成果:
- 高甲基化率潜力和hgcA转录表明有意义的现场MeHg形成.
- 添加酸盐减少了甲基化,证实了硫酸盐还原的作用.
- 减少硫酸盐的细菌在hgcA转录中占主导地位 (> 50%),尽管其丰度较低 (< 10%).
- 一种arsR类调节剂与减少hgcA表达有关.
结论:
- 减少硫酸盐的细菌是 MeHg 产生的关键驱动力,在温的淡水湖中.
- 现场MeHg形成是MeHg向水柱的主要来源.
- 微生物调节,包括转录控制,影响MeHg动态.
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