Insights from metagenomic, metatranscriptomic, and molecular ecological network analyses into the effects of chromium nanoparticles on activated sludge system
Insights from metagenomic, metatranscriptomic, and molecular ecological network analyses into the effects of chromium nanoparticles on activated sludge system
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DOI：
10.1007/s11783-020-1239-8
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发表时间：
2020-04
影响因子：
6.4
通讯作者：
Q. Zheng;Minglu Zhang;Tingting Zhang;Xinhui Li;Minghan Zhu;Xiaohui Wang
中科院分区：
文献类型：
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作者：
Q. Zheng;Minglu Zhang;Tingting Zhang;Xinhui Li;Minghan Zhu;Xiaohui Wang
研究了铬纳米颗粒（Cr NPs）对活性污泥（AS）系统脱氮除磷性能及细菌结构的影响。并通过分子生态网络（MENs）探讨了细菌间的相互作用。最后研究了AS系统中与脱氮除磷相关的功能基因及其表达模式的变化。结果表明，1 mg/L的CrNPs长期暴露显著促进了AS系统的絮凝过程和除磷效果。除磷微生物中脱硝菌属、索氏菌属、脱氯单胞菌属和脱氟球菌属的相对丰度显著增加，聚磷菌聚磷菌（PAOs）的相对丰度显著增加，糖原菌竞争菌（GAOs）的相对丰度显著下降。此外，宏基因组和元转录组分析表明，大多数与除磷和除磷相关的属的数量都有了很大的增加，相应的转录量也有了很大的增加。最后，MENs分析表明，虽然在铬纳米颗粒的存在下，整个网络变得更小，更松散，与氮和磷的去除相关的成员之间的微生物连接增强。除磷菌和聚磷菌的丰度增加、功能基因转录增加以及相互作用增强可能与促进除磷过程和除磷有关。
The objectives of this study were to investigate the influence of chromium nanoparticles (Cr NPs) on the nitrogen and phosphorus removal performance and the bacterial structures of an activated sludge (AS) system. Also, we through molecular ecological networks (MENs) discussed the bacterial interactions. At last we researched the change of the functional genes and their expression patterns related to nitrogen and phosphorus removal in an AS system. The results showed that long-term exposure to 1 mg/L Cr NPs significantly promoted the denitrifying process and phosphorus removal in the AS system. The relative abundance of denitrifying and phosphorus removal microorganisms, such asDenitratisoma, Thauera, Dechloromonas, andDefluviicoccus, increased significantly.Candidatus Accumulibacter, well-known as polyphosphate-accumulating organisms (PAOs), increased significantly; the relative abundance ofCandidatus Competibacter, known as glycogen-accumulating organisms (GAOs), decreased significantly. Furthermore, metagenomic and metatranscriptomic analysis revealed that most of the genera related to denitrifying and phosphorus removal had greatly increased, according to the quantities of denitrifying and phosphorus genes, and the corresponding transcription likewise greatly increased. Lastly, MENs analysis showed that although the overall network became smaller and looser in the presence of Cr NPs, the microbial connections among members related to nitrogen and phosphorus removal were enhanced. The abundance increases of denitrifiers and PAOs, and their increased transcription of functional genes, together with the enhanced interactions may be associated with the promotion of the denitrifying process and phosphorus removal.