Water and Environmental Research Center, University of Alaska Fairbanks, 1760 Tanana Loop, Fairbanks, AK 99775, USA.
Mineral Industry Research Laboratory, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
Environ Sci Process Impacts. 2021 Dec 15;23(12):2007-2020. doi: 10.1039/d1em00256b.
Failure of sulfate-reducing bacteria (SRB)-mediated treatment of acid mine drainage (AMD) in cold regions due to inhibition of bacteria by acidic pH and low temperature can be overcome by enriching psychrophilic and acidophilic microbial consortia from local metal-rich sediments. In this study, we enriched microbial consortia from Arctic mine sediments at varying pH (3-7) and temperatures (15-37 °C) under anaerobic conditions with repeated sub-culturing in three successive stages, and analyzed the microbial community using 16S rRNA gene sequencing. The enriched SRB genera resulted in high sulfate reduction (85-88%), and significant metal removal (49-99.9%) during the initial stages (stage 1 and 2). Subsequently, sub-culturing the inoculum at pH 3-4.5 resulted in lower sulfate reduction (9-34%) due to the inhibition of SRB by accumulated acetic acid (0.3-9 mM). The microbial metabolic interactions for successful sulfate and metal removal involved initial glycerol co-fermentation to acetic acid at acidic pH (by , , , and fermentative bacteria including and ), followed by acetic acid oxidation to CO and H (by ) at neutral pH, and subsequent H utilization (by ). The results, including the structural and functional properties of enriched microbial consortia, can inform the development of effective biological treatment strategies for AMD in cold regions.
在寒冷地区，由于酸性 pH 值和低温抑制了细菌的生长，硫酸盐还原菌 (SRB) 介导的处理酸性矿山排水 (AMD) 的方法可能会失败。但是，可以通过从富含金属的当地沉积物中富集耐寒和嗜酸微生物群落来克服这一问题。在这项研究中，我们在厌氧条件下，从北极矿山沉积物中在不同的 pH 值（3-7）和温度（15-37°C）下进行了重复的亚培养，以富集微生物群落，并使用 16S rRNA 基因测序分析了微生物群落。在初始阶段（第 1 阶段和第 2 阶段），富集的 SRB 属导致高硫酸盐还原（85-88%）和显著的金属去除（49-99.9%）。随后，在 pH 3-4.5 下亚培养接种物会导致硫酸盐还原率降低（9-34%），这是由于积累的乙酸（0.3-9 mM）对 SRB 的抑制作用。成功进行硫酸盐和金属去除的微生物代谢相互作用涉及初始甘油共发酵到酸性 pH 值下的乙酸（由 、 、 、 和发酵细菌包括 和 ），随后在中性 pH 值下乙酸氧化为 CO 和 H （由 ），以及随后的 H 利用（由 ）。这些结果，包括富集微生物群落的结构和功能特性，可以为寒冷地区 AMD 的有效生物处理策略的开发提供信息。
