The Weimin Sun research group has recently published an article entitled “VV reduction by Polaromonas spp. in vanadium mine tailings” in the prestigious journal Environmental Science & Technology. The study provided an in depth investigation of the microbial responses to elevated vanadium concentration using a combination of the field survey, lab experiments, and bioinformatic analysis.
Vanadium (V) is an important metal with critical industrial and medical applications. Elevated V contamination, however, can be a threat to environmental and human health. Microorganisms can reduce the more toxic and mobile VV to the less toxic and immobile VIV, which could be a detoxification and energy metabolism strategy adopted by V reducing bacteria (VRB). The limited understanding of microbial responses to V contamination and the mechanisms for VV reduction, however, hampers our capability to attenuate V contamination. This study focused on determining the microbial responses to elevated V concentration and the mechanisms of VV reduction in a V tailing. The bacterial communities were characterized and compared between the V tailing and the less contaminated adjacent soils. Further, VV-reducing enrichments indicated that bacteria associated with Polaromonas, a genus belonging to the family Burkholderiaceae, were potentially responsible for VV reduction. Retrieved metagenome assembled genomes (MAGs) suggested that the Polaromonas spp. encoded genes (cymA, omcA, and narG) that were responsible for VV reduction. Additionally, Polaromonas spp. was metabolically versatile and could use both organic and inorganic electron donors. The metabolic versatility of Polaromonas spp. may be important for their ability to flourish in the V tailings.