人工湿地污水处理系统中植物套种模式根际微生物多样性研究

Analysis of Microorganism Species Diversity in Plant Intercropping Models in a Wetland System Constructed for Treatment of Municipal Sewage

采用选择性平板培养基法和PCR-DGGE法,比较研究了人工湿地污水处理系统中植物套种模式和无植物单元在不同季节和不同单元之间根际微生物多样性.结果表明,植物套种模式的根际微生物数量明显高于无植物模式,夏季明显多于冬季.在三级串联的处理单元之间,夏季根际微生物数量呈现"少-多-少"的变化规律,冬季无明显的变化规律.UPGMA聚类分析显示,除冬季个别样外,相同季节的处理均聚集在同一个分支下,且微生物多样性指数夏季高于冬季.得到的5个差异序列(DF1～DF5),经BLAST比较,分别找到源性最近的已知类群,分别为大肠杆菌、柠檬酸细菌、变形菌、产酸克雷伯菌、伯克霍尔德氏菌.BLASTX比较发现DF1与分支杆菌噬菌体和解淀粉芽孢杆菌生命活动相关;DF2是一种保守假设ATP结合蛋白;DF3与蜡样芽孢杆菌生命活动相关;DF4参与微生物的分解代谢活动;DF5与微生物通过代谢分解有机物有关.

The selective culture method and PCR-DGGE technology were applied to analyze the number and the biodiversity of micro-organism species in cells with plant intercropping models and without plants in different seasons in a wetland system constructed for treatment of municipal sewage.The results showed that the numbers of microorganisms were considerably larger in the cells with plant intercropping models than those without plants,while the number of microorganisms was apparently larger in summer than that in winter in all treatments.Along the three-sequenced treatment cells with plant intercropping models a ＂low-high-low＂ changing trend in the numbers of microorganisms in summer.The UPGMA cluster analysis showed that the treatments in the same season were clustered in the same branch except for a few samples in winter and the biodiversity index was consistently higher in summer than that in winter.Five different sequences（DF1-DF5）were obtained through BLAST analysis and retrieval.The closest known origin groups were located as Escherichia coli,Citrobacter sp.,Proteus sp.,Klebsiella oxytoca,and Burkholderia sp.respectively.The BLASTX comparison test showed that DF1 closely related to the activities of the Mycobacterium bacillus and the Bacillus amyloliquefaciens,DF2 functioned as a conservative potential ATP binding protein,DF3 related to the activities of the Bacillus cereus spore,DF4 was involved in catabolism metabolism of microorganism and DF5 played an important role in decomposition of organic matters.