{"title":"Isolation and identification of anaerobic molybdenum(VI)-reducing bacteria in molybdenum mine sediments in Korea","authors":"Vo Anh Khoa Nguyen , Hyeop-Jo Han , Jong-Un Lee","doi":"10.1016/j.gexplo.2025.107711","DOIUrl":null,"url":null,"abstract":"<div><div>This study was conducted to isolate and identify anaerobic molybdenum(VI)-reducing bacteria from sediments and soils collected from molybdenum mine areas in Korea. Molybdenum, a trace element vital for biological systems, can pose environmental risks when present in high concentrations, particularly in mining areas. Soil and sediment samples were collected, and the physicochemical properties including pH and metal content were analyzed. Two bacterial strains, identified as <em>Klebsiella aerogenes</em> and <em>Klebsiella oxytoca</em>, were isolated and exhibited significant molybdenum(VI) reduction under anaerobic conditions, reducing over 90 % of the molybdenum within 72 h at an initial concentration of 15 mM. The study further explored the effects of alternative electron acceptors and donors, revealing that nitrate and sulfate did not inhibit Mo(VI) reduction, while acetate had little effect. The reduction likely occurred via fermentative processes rather than respiratory reduction, as evidenced by the absence of oxygen consumption, the preferential use of glucose as an electron donor, and the lack of competition from alternative electron acceptors such as nitrate and sulfate under anaerobic conditions. These findings suggest that microbial Mo(VI) reduction in mining environments could play a critical role in the geochemical cycling of molybdenum and provide a foundational basis for developing bioremediation strategies specifically tailored for mining-affected ecosystems.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"272 ","pages":"Article 107711"},"PeriodicalIF":3.4000,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Geochemical Exploration","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0375674225000433","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
This study was conducted to isolate and identify anaerobic molybdenum(VI)-reducing bacteria from sediments and soils collected from molybdenum mine areas in Korea. Molybdenum, a trace element vital for biological systems, can pose environmental risks when present in high concentrations, particularly in mining areas. Soil and sediment samples were collected, and the physicochemical properties including pH and metal content were analyzed. Two bacterial strains, identified as Klebsiella aerogenes and Klebsiella oxytoca, were isolated and exhibited significant molybdenum(VI) reduction under anaerobic conditions, reducing over 90 % of the molybdenum within 72 h at an initial concentration of 15 mM. The study further explored the effects of alternative electron acceptors and donors, revealing that nitrate and sulfate did not inhibit Mo(VI) reduction, while acetate had little effect. The reduction likely occurred via fermentative processes rather than respiratory reduction, as evidenced by the absence of oxygen consumption, the preferential use of glucose as an electron donor, and the lack of competition from alternative electron acceptors such as nitrate and sulfate under anaerobic conditions. These findings suggest that microbial Mo(VI) reduction in mining environments could play a critical role in the geochemical cycling of molybdenum and provide a foundational basis for developing bioremediation strategies specifically tailored for mining-affected ecosystems.
期刊介绍:
Journal of Geochemical Exploration is mostly dedicated to publication of original studies in exploration and environmental geochemistry and related topics.
Contributions considered of prevalent interest for the journal include researches based on the application of innovative methods to:
define the genesis and the evolution of mineral deposits including transfer of elements in large-scale mineralized areas.
analyze complex systems at the boundaries between bio-geochemistry, metal transport and mineral accumulation.
evaluate effects of historical mining activities on the surface environment.
trace pollutant sources and define their fate and transport models in the near-surface and surface environments involving solid, fluid and aerial matrices.
assess and quantify natural and technogenic radioactivity in the environment.
determine geochemical anomalies and set baseline reference values using compositional data analysis, multivariate statistics and geo-spatial analysis.
assess the impacts of anthropogenic contamination on ecosystems and human health at local and regional scale to prioritize and classify risks through deterministic and stochastic approaches.
Papers dedicated to the presentation of newly developed methods in analytical geochemistry to be applied in the field or in laboratory are also within the topics of interest for the journal.