College of Resources and Environment, Shandong Agricultural University, Taian, 271018, China.
College of Water Sciences, Beijing Normal University, Beijing, 100875, China.
Sci Rep. 2020 Jun 1;10(1):8818. doi: 10.1038/s41598-020-65795-3.
This study explored the effect of 70-mT magnetic field on wastewater treatment capacity for activated sludge in long-term laboratory-scale experiments. Metagenomic sequencing were conducted based on Illumina HiSeq 2000 platform after DNA extraction of the activated sludge. Then the effect of the magnetic field on the microbial unigene and metabolic pathways in activated sludge was investigated. As a result, higher pollutant removal was observed at 70 mT, with which the elimination of total nitrogen (TN) was the most effective. Functional genes annotated based on eggNOG database showed that unigenes related to information storage and processing were enhanced by the magnetic field. For CAZy classification, category such as glycosyl transferases was more abundant in the reactor with magnetic field, which has been shown to promote the entire energy supply pathway. Additionally, in the KEGG categories, unigenes related to signaling molecules and interaction were significantly inhibited. Through the enrichment analysis of the nitrogen metabolism pathway, the magnetic field inhibited anabolic nitrate reduction by significantly inhibiting enzymes such as [EC:1.7.7.2], [EC:1.7.7.1], [EC:3.5.5.1], [EC:1.4.1.2] and [EC:4.2.1.1], which are related to the improvement of the denitrification ability. This study can provide insight for future research on the response mechanism of activated sludge to magnetic fields.
本研究通过长期实验室规模实验，探索了 70mT 磁场对活性污泥处理废水能力的影响。从活性污泥中提取 DNA 后，基于 Illumina HiSeq 2000 平台进行宏基因组测序。然后研究了磁场对活性污泥中微生物基因和代谢途径的影响。结果表明，70mT 时污染物去除效果更高，其中总氮（TN）的去除效果最为显著。基于 eggNOG 数据库注释的功能基因显示，与信息存储和处理相关的基因被磁场增强。在 CAZy 分类中，糖苷转移酶等类别在有磁场的反应器中更为丰富，这已被证明可促进整个能量供应途径。此外，在 KEGG 类别中，与信号分子和相互作用相关的基因显著受到抑制。通过氮代谢途径的富集分析，磁场通过显著抑制[EC：1.7.7.2]、[EC：1.7.7.1]、[EC：3.5.5.1]、[EC：1.4.1.2]和[EC：4.2.1.1]等与提高反硝化能力相关的酶，抑制了同化硝酸盐还原。本研究可为未来研究活性污泥对磁场的响应机制提供参考。
