Anthropogenic remediation of heavy metals selects against natural microbial remediation

In an era of unprecedented environmental change, there have been increasing ecological and global public health concerns associated with exposure to anthropogenic pollutants. While there is a pressing need to remediate polluted ecosystems, human intervention might unwittingly oppose selection for natural detoxification, which is primarily carried out by microbes. We test this possibility in the context of a ubiquitous chemical remediation strategy aimed at targeting metal pollution: the addition of lime-containing materials. Here we show that raising pH by liming decreased the availability of toxic metals in acidic mine-degraded soils, but as a consequence selected against microbial taxa that naturally remediate soil through the production of metal-binding siderophores. Our results therefore highlight the crucial need to consider the eco-evolutionary consequences of human environmental strategies on microbial ecosystem services and other traits.在环境变革空前的时代，人为源污染物（anthropogenic pollutants）暴露引发的生态与全球公共健康问题日益凸显。当前，修复受污染生态系统的需求极为迫切，但人类干预可能在无意中抑制了以微生物为主要执行者的自然解毒作用所对应的自然选择。我们针对一种用于治理金属污染的通用化学修复策略——添加含石灰材料——检验了这一可能性。研究结果表明，通过施石灰改良提升土壤pH值，可降低酸性矿山退化土壤中有毒金属的生物有效性，但该操作同时会对通过合成金属结合嗜铁素（siderophores）自然修复土壤的微生物类群产生负选择作用。因此，本研究结果凸显出一项关键需求：需考量人类环境策略对微生物生态系统服务（microbial ecosystem services）及其他性状产生的生态进化（eco-evolutionary）效应。