The Microbiology of Metal Mine Waste: Bioremediation Applications and Implications for Planetary Health. (5th October 2021)

• Record Type: Journal Article
• Authors: Newsome, Laura; Falagán, Carmen
• Is Part Of: GeoHealth. Volume 5:Number 10(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-10-05
• Subjects: bacteria -- fungi -- mining -- toxicity -- biogeochemistry -- remediation; Environmental health -- Periodicals; Electronic journals; Periodicals; 616.98
• DOI: 10.1029/2020GH000380
• Languages: English
• ISSNs: 2471-1403

Abstract

Abstract: Mine wastes pollute the environment with metals and metalloids in toxic concentrations, causing problems for humans and wildlife. Microorganisms colonize and inhabit mine wastes, and can influence the environmental mobility of metals through metabolic activity, biogeochemical cycling and detoxification mechanisms. In this article we review the microbiology of the metals and metalloids most commonly associated with mine wastes: arsenic, cadmium, chromium, copper, lead, mercury, nickel and zinc. We discuss the molecular mechanisms by which bacteria, archaea, and fungi interact with contaminant metals and the consequences for metal fate in the environment, focusing on long‐term field studies of metal‐impacted mine wastes where possible. Metal contamination can decrease the efficiency of soil functioning and essential element cycling due to the need for microbes to expend energy to maintain and repair cells. However, microbial communities are able to tolerate and adapt to metal contamination, particularly when the contaminant metals are essential elements that are subject to homeostasis or have a close biochemical analog. Stimulating the development of microbially reducing conditions, for example in constructed wetlands, is beneficial for remediating many metals associated with mine wastes. It has been shown to be effective at low pH, circumneutral and high pH conditions in the laboratory and at pilot field‐scale. Further demonstration of this technology at full field‐scale is required, as is more research to optimize bioremediation and to investigate combined remediation strategies. Microbial activity has the potential to mitigate the impacts of metal mine wastes, and therefore lessen the impact of this pollution on planetary health. Plain Language Summary: Mine waste is a serious global environmental issue. Poorly managed mine wastes are responsible for polluting our environment with toxic metals and metalloids. Microbes can live in mine wastes, even when they contain high levels of metals. These microbes can lessen the environmental impact of mine wastes by helping them become colonized by plants, and by changing the metals into forms that are less mobile in the environment. For example, some microbes can make minerals that stop metals dissolving into rainwater, and therefore prevent them from ending up in rivers. But on the other hand, some microbes can increase the amount of metals that dissolve into waters by producing acidity. This article describes the impact of microbial activity on the metals most commonly found in mine wastes, and how we can encourage beneficial microbial activities to reduce the environmental impact of mine wastes. Key Points: Microbes colonize and inhabit mine wastes, they tolerate high concentrations of metals and contribute to soil functioning and plant growth Microbes transform metal speciation and environmental mobility, through metabolism, biogeochemical cycling and metal resistance mechanisms Beneficial microbial activity can be stimulated to remediate metal‐containing mine wastes, but more long‐term field studies are required