BRIMM Researcher Sue Baldwin and co-authors Frank Nkansah-Boadu and Ido Hatam (both of the Department of Chemical and Biological Engineering) have discovered new bacterial species capable of reducing selenium and nitrate simultaneously. Selenium in mine-impacted water is often difficult to remove due to the presence of nitrate; this new method is able to overcome this complication. The team obtained the genomes for these previously unknown microorganisms through the use of metagenomic sequencing.
Read the abstract below and keep an eye out for this upcoming publication.
Citation and Abstract
Nkansah-Boadu, F., Hatam, I., Baldwin, S.A., 2021. Microbial consortia capable of reducing selenate in the presence of nitrate enriched from coalmining-impacted environments. Appl. Microbiol. Biotechnol. 105, 1287–1300. https://doi.org/10.1007/s00253-020-11059-z
Biological treatment to remove dissolved selenium from mine-impacted water is often inhibited by the co-contaminant nitrate. In this work we enriched microbial consortia capable of removing dissolved selenium in the presence of nitrate from native bacteria at sites impacted by coalmine seepages with elevated concentrations of Se, nitrate and sulphate. Enrichments were collected from sediments in different vegetated or non-vegetated seepage collection ponds, and all demonstrated the potential for dissolved selenium removal. Nitrate inhibited dissolved selenium removal rates in four of these enrichments. However, microorganisms enriched from a mine-impacted natural vegetated marsh removed dissolved Se and nitrate simultaneously. Additionally, enrichments from one seepage collection pond achieved enhanced dissolved selenium removal in the presence of nitrate. Based on functional metagenomics, the dominant species with the metabolic capacity for selenate reduction were classified in Orders Enterobacterales and Clostridiales. Most putative selenate reductases identified as either ygfK, associated with selenoprotein synthesis or production of methylated organoselenium compounds, and narG, nitrate reductases with an affinity also for selenate.
More exciting research from the Mining Microbiome group includes the following publications:
Baldwin, S. A., Taylor, J. C., & Ziels, R. (2019). Genome-resolved metagenomics links microbial dynamics to failure and recovery of a bioreactor removing nitrate and selenate from mine-influenced water. Biochemical Engineering Journal, 151, 107297. https://doi.org/10.1016/j.bej.2019.107297
Satyro, S., Li, H., Dehkhoda, A. M., McMillan, R., Ellis, N., & Baldwin, S. A. (2021). Application of Fe-biochar composites for selenium (Se+6) removal from aqueous solution and effect of the presence of competing anions under environmentally relevant conditions. Journal of Environmental Management, 277, 111472. https://doi.org/10.1016/j.jenvman.2020.111472