Contamination of aquifers by a combination of vanadate [V(V)] and nitrate (NO) is widespread nowadays. Although bioremediation of V(V)- and nitrate-contaminated environments is possible, only a limited number of functional species have been identified to date. The present study demonstrates the effectiveness of V(V) reduction and denitrification by a denitrifying bacterium sp. strain BoFeN1. The V(V) removal efficiency was 76.5 ± 5.41 % during 120 h incubation, with complete removal of NO within 48 h. Inhibitor experiments confirmed the involvement of electron transport substances and denitrifying enzymes in the bioreduction of V(V) and NO. Cyt c and riboflavin were important for extracellular V(V) reduction, with quinone and EPS more significant for NO removal. Intracellular reductive compounds including glutathione and NADH directly reduce V(V) and NO. Reverse transcription quantitative PCR confirmed the important roles of and genes in regulating V(V) reduction and denitrification. Bioaugmentation by strain BoFeN1 increased V(V) and NO removal efficiency by 55.3 % ± 2.78 % and 42.1 % ± 1.04 % for samples from a contaminated aquifer. This study proposes new microbial resources for the bioremediation of V(V) and NOcontaminated aquifers, and contributes to our understanding of coupled vanadium, nitrogen, and carbon biogeochemical processes.

中文翻译：

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反硝化细菌 Acidovorax sp 介导的钒酸盐还原和反硝化的多种途径。菌株BoFeN1

如今，钒酸盐 [V(V)] 和硝酸盐 (NO) 的组合对含水层的污染非常普遍。尽管对 V(V) 和硝酸盐污染环境进行生物修复是可能的，但迄今为止仅发现了有限数量的功能物种。本研究证明了反硝化细菌对 V(V) 还原和反硝化的有效性。菌株 BoFeN1。 120 小时孵育期间，V(V) 去除效率为 76.5 ± 5.41 %，48 小时内完全去除 NO。抑制剂实验证实电子传递物质和反硝化酶参与V(V)和NO的生物还原。细胞色素 c 和核黄素对于细胞外 V(V) 降低很重要，醌和 EPS 对于 NO 去除更重要。包括谷胱甘肽和 NADH 在内的细胞内还原化合物直接还原 V(V) 和 NO。逆转录定量PCR证实了 和 基因在调节V(V)还原和反硝化中的重要作用。对于来自受污染含水层的样品，BoFeN1 菌株的生物强化将 V(V) 和 NO 去除效率提高了 55.3 % ± 2.78 % 和 42.1 % ± 1.04 %。这项研究提出了用于 V(V) 和 NO 污染含水层生物修复的新微生物资源，并有助于我们了解钒、氮和碳耦合生物地球化学过程。