高原高寒污水处理系统的微生物群落特征

为研究高原高寒污水处理系统活性污泥的微生物群落结构及多样性，以拉萨、云南、四川的3座高原污水厂作为实验组，同时以重庆2座非高原污水厂作为对照，采用PCR-DGGE技术对比分析了高原与非高原污水厂的微生物特性.研究表明：高原污水厂样品与非高原样品在聚类中展现出了较为疏远的关系，微生物群落区别明显.受强紫外线辐照的抑制，高原高寒污水处理系统微生物多样性的平均水平显著低于非高原污水厂，较低的微生物多样性是导致高原高寒地区污染物去除效果不佳的一项重要原因.群落构成方面，共鉴定出16个优势菌属，对应Proteobacteria、Bacteroidetes、Firmicutes、Verrucomicrobia 4个门.组间差异分析结果发现，高原组中丰度显著偏高的菌属只有Prosthecobacter，该菌在污水厂内分布广泛，且能够适应高原低温的条件.对于大多数活性污泥微生物而言，高原强紫外线是不利的生存条件.因此，减少高原露天污水处理系统的紫外辐照，是提升污水处理效能的一个潜在措施.

Microbial community characteristics of wastewater treatment systems in high-altitude and cold regions

To investigate the microbial structure and diversity of the wastewater treatment systems in plateau and cold regions, three plateau wastewater treatment plants (WWTPs) in Lhasa, Yunnan and Sichuan were chosen as experimental group, and two non-plateau WWTPs in Chongqing were used for comparison. Polymerase chain reaction-Denaturing gradient gel electrophoresis (PCR-DGGE) was adapted to reveal the microbial characteristics of plateau and non-plateau WWTPs. The cluster results showed that plateau samples exhibited far distances from non-plateau samples, and the microbial community displayed an apparent difference. The average diversity of plateau WWTPs was lower than that of non-plateau WWTPs, which might be due to the significant inhibitory effect of ultraviolet (UV) radiation in plateau regions. As a result, the pollutant removal efficiency in plateau WWTPs was not satisfied as expected. For community composition, a total of 16genera were identified, which belong to the phyla of Proteobacteria, Bacteroidetes, Firmicutes and Verrucomicrobia. The difference analysis between groups showed that there was only one genus, Prosthecobacter, significantly enriched in plateau group, which is widely distributed in WWTPs and can adapt to the low temperature in the plateau. But for most activated sludge bacteria, high altitude and UV irradiation is an unfavorable living condition. Therefore, shading the UV radiation for the open WWTPs is a potential way to improve the wastewater treatment performance in plateau and cold regions.