Mining and other industrial activities worldwide have resulted in Seenriched surface soils, which pose risks to human and environmental health. Although not well studied, microbial activity can alter Se bioavailability and distribution, even in oxic environments. We used high-throughput sequencing to profile bacterial and fungal communities inhabiting mine soils in southeastern Idaho, comparing mined and unmined locations within two reclaimed phosphate mine areas containing various Se concentrations. The goal was to determine whether microbial communities differed in (i) different mines, (ii) mined areas compared to unmined areas, and (iii) various soil Se concentrations. Though reclamation occurred 20 to 30 years ago, microbial community structures in mined soils were significantly altered compared to unmined soils, suggesting persistent mining-related impacts on soil processes. Additionally, operational taxonomic unit with a 97% sequence similarity cutoff (OTU0.03) richness and diversity were significantly diminished with increasing Se, though not with other geochemical parameters, suggesting that Se contamination shapes communities in favor of Se-tolerant microorganisms. Two bacterial phyla, Actinobacteria and Gemmatimonadetes, were enriched in high-Se soils, while for fungi, Ascomycota dominated all soils regardless of Se concentration. Combining diversity analyses and taxonomic patterns enables us to move toward connecting physiological function of microbial groups to Se biogeochemical cycling in oxic soil environments.
Bibliographical noteFunding Information:
Research was supported by a Smithsonian Institution Competitive Grants Program for Science (to C.M.S. and C.E.R.), a National Science Foundation (NSF) EAR postdoctoral fellowship (to C.E.R., grant 1452666), and MnDRIVE Environment (to C.M.S.). This work was carried out in part using computing resources at the Minnesota Supercomputing Institute (MSI; http://www.msi.umn.edu) at the University of Minnesota. We acknowledge Lauren C. Cline and Shawn P. Brown for helpful discussions and Kelly Duhn, Elizabeth Carlson, and Jordan Max Loy for field and laboratory support. We also thank Agrium/Nu-West Industries, Inc., the U.S. Forest Service, and Soda Springs Ranger District for site access, and specifically Jon Bronson (Agrium/Nu-West), Kelsey Franko (ARCADIS), and Doug Peterson (ARCADIS) for on-site coordination and field suppor
© 2018 American Society for Microbiology.
- Microbial ecology