Bomberg Malin, Mäkinen Jarno, Salo Marja, Arnold Mona
VTT Technical Research Centre of Finland, P.O. Box 1000, FIN-02044 Espoo, Finland.
Microorganisms. 2017 Sep 20;5(3):61. doi: 10.3390/microorganisms5030061.
Sulfate-rich mine water must be treated before it is released into natural water bodies. We tested ethanol as substrate in bioreactors designed for biological sulfate removal from mine water containing up to 9 g L sulfate, using granular sludge from an industrial waste water treatment plant as inoculum. The pH, redox potential, and sulfate and sulfide concentrations were measured twice a week over a maximum of 171 days. The microbial communities in the bioreactors were characterized by qPCR and high throughput amplicon sequencing. The pH in the bioreactors fluctuated between 5.0 and 7.7 with the highest amount of up to 50% sulfate removed measured around pH 6. Dissimilatory sulfate reducing bacteria (SRB) constituted only between 1% and 15% of the bacterial communities. Predicted bacterial metagenomes indicated a high prevalence of assimilatory sulfate reduction proceeding to formation of l-cystein and acetate, assimilatory and dissimilatory nitrate reduction, denitrification, and oxidation of ethanol to acetaldehyde with further conversion to ethanolamine, but not to acetate. Despite efforts to maintain optimal conditions for biological sulfate reduction in the bioreactors, only a small part of the microorganisms were SRB. The microbial communities were highly diverse, containing bacteria, archaea, and fungi, all of which affected the overall microbial processes in the bioreactors. While it is important to monitor specific physicochemical parameters in bioreactors, molecular assessment of the microbial communities may serve as a tool to identify biological factors affecting bioreactor functions and to optimize physicochemical attributes for ideal bioreactor performance.
富含硫酸盐的矿井水在排放到天然水体之前必须进行处理。我们在设计用于从含硫酸盐高达9 g/L的矿井水中生物去除硫酸盐的生物反应器中，以乙醇作为底物进行了测试，使用来自工业废水处理厂的颗粒污泥作为接种物。在最长171天的时间里，每周测量两次pH值、氧化还原电位以及硫酸盐和硫化物的浓度。通过定量聚合酶链反应（qPCR）和高通量扩增子测序对生物反应器中的微生物群落进行了表征。生物反应器中的pH值在5.0至7.7之间波动，在pH约为6时，去除的硫酸盐量最高可达50%。异化硫酸盐还原菌（SRB）仅占细菌群落的1%至15%。预测的细菌宏基因组表明，同化硫酸盐还原生成L-半胱氨酸和乙酸盐、同化和异化硝酸盐还原、反硝化以及乙醇氧化为乙醛并进一步转化为乙醇胺但不转化为乙酸盐的情况普遍存在。尽管努力在生物反应器中维持生物硫酸盐还原的最佳条件，但只有一小部分微生物是SRB。微生物群落高度多样化，包含细菌、古菌和真菌，所有这些都影响了生物反应器中的整体微生物过程。虽然在生物反应器中监测特定的物理化学参数很重要，但对微生物群落的分子评估可作为一种工具，用于识别影响生物反应器功能的生物因素，并优化物理化学属性以实现理想的生物反应器性能。
