废水生物处理过程中污泥的微生物种群结构和PAHs降解菌研究进展

Microbial community structure and PAHs-degrading bacteria of activated sludge in biological wastewater treatment process

含有难降解有机物的工业废水严重威胁生态和人类健康.活性污泥法是工业废水处理的核心技术,细菌种群在其中发挥重要作用.研究污泥的微生物群体结构不仅为废水处理厂的稳定运行提供指导,而且可以提高废水处理效率.基于高通量序列分析的细菌门/属分类或操作分类单元聚类分析研究表明,市政污泥的微生物多样性存在地域性差异;不同的工业废水污泥的微生物群体组成各有特点,在门/纲分类水平上明显不同于市政污泥;焦化废水污泥微生物种群结构在门分类水平上具有相似的微生物组成;水质是微生物种群结构形成的主要驱动力,环境条件也有一定的影响;此外,多种多环芳烃降解菌已经被鉴定,并分析了其降解途径和关键酶基因.本文主要综述这几方面的研究进展.

Industrial wastewater containing refractory organics has posed serious threat towards ecology and human health. The activated sludge methods for biological treatment are regarded as the core treatment units for industrial wastewater purification, and bacteria in activated sludge wastewater treatment bioreactors play a central role. A better understanding of microbial communities in sludge can not only provide important guidance in stable operation of wastewater treatment systems,but also improve the removal of pollutants. The clear geographical differences of microbial community diversity among the activated sludge in domestic wastewater treatment processes were revealed by cluster analyses based on abundances of the operational taxonomic units or the genus /phyla assigned by pyrosequencing of 16 S rD NA. Each industrial activated sludge system exhibited a unique bacterial community composition,which was clearly distinct from the common profile of bacterial phyla / classes observed in municipal plants. The community structures of activated sludge in coking wastewater treatment plants exhibited a similar community composition at each taxonomic level. The wastewater characteristics are likely to be the major determinant that drives bacterial composition at high taxonomic ranks. The operational parameters have a great impact on the bacterial community structure. In addition,a variety of PAHs-degrading bacteria are identified,and the key enzyme and pathway involved in PAH degradation are characterized. These results have potential applications for strengthening the biological degradation. This review highlights several promising areas to be explored in future.