Abstract:[Background] Perchlorate is a new water pollutant, and using microorganisms for harmless treatment of industrial wastewater containing perchlorate has high efficiency, low costs, and environmental friendliness. [Objective] However, the resources of local perchlorate- reducing bacteria with fast growth, strong activity, and high reduction efficiency are extremely scarce and urgently need to be explored. [Methods] In this study, we isolated and screened perchlorate-reducing bacteria from activated sludge, identified their species using molecular biology techniques, and explored the physiological and metabolic characteristics of the isolated strains through microbial culture experiments. [Results] Finally, a perchlorate-reducing bacterial strain QD19-16 was isolated and identified as Brucella sp. by 16S rRNA gene analysis. Strain QD19-16 was an anaerobic facultative bacterium, with optimal growth at 30 ℃ and pH 7.0. Strain QD19-16 demonstrated a variety of metabolic activities and showed the ability to use acetate, yeast extract, and lactic acid as electron donors and perchlorate, chlorate, sulfate, and oxygen as electron acceptors. Under anaerobic conditions, the maximum specific growth rate (μmax) of strain QD19-16 using perchlorate as an electron acceptor was 0.279 d−1, with a half-saturation constant (Ks) of 0.294 mmol/L for perchlorate. [Conclusion] Brucella sp. QD19-16 is the first reported perchlorate-reducing bacterium of Brucella, expanding the distribution of perchlorate-reducing bacteria of Proteobacteria. Strain QD19-16 can be applied in assembling the microbial communities for perchlorate reduction in anaerobic bioreactors.
