Please wait a minute...
浙江大学学报（农业与生命科学版）
浙江大学学报(农业与生命科学版)  2013, Vol. 39 Issue (5): 545-555    DOI: 10.3785/j.issn.1008-9209.2013.03.191
资源与环境科学     
土霉素对活性污泥微生物群落结构的影响
唐璐， 牛成镇， 吕镇梅*
（浙江大学生命科学学院，杭州310058）
Dynamic change of microbial community structure of activated sludge influenced by oxytetracycline in wastewater
TANG Lu, NIU Chengzhen, LYU Zhenmei*
(College of Life Sciences, Zhejiang University, Hangzhou 310058, China)
 全文: PDF(5006 KB)   HTML ( ) 
摘要： 为了解在土霉素（oxytetracycline, OTC）胁迫下活性污泥中微生物的作用机制，以分别含0、0.1、5、20、60 mg/L OTC人工废水的活性污泥为对象，应用聚丙烯酰胺凝胶电泳技术（denaturing gradient gel electrophoresis, DGGE）研究活性污泥微生物群落结构随不同废水OTC负荷及反应器运行时间的动态变化特点，并结合扫描电镜技术对活性污泥的形态进行观察。结果表明：在反应器运行过程中，对照组（未添加OTC）比处理组（添加不同质量浓度OTC）的活性污泥具有更丰富的微生物相。仅在对照组中发现了丝状菌；短杆菌在处理组中的比例明显降低，球状菌表现出更强的OTC适应性。在运行至88 d时，对照组和OTC质量浓度≤20 mg/L的处理组中均出现较多体型较大的球状微生物。活性污泥中主要优势菌属于变形菌门 （Proteobacteria）和拟杆菌门（Bacteroidetes），但各菌属表现出不同的OTC抗性，在不同处理组间出现不同优势菌群，分别在其相应的废水处理中发挥着作用，从而使活性污泥的废水处理效率逐渐恢复。这些结果说明活性污泥微生物群落结构及其废水处理效率具有OTC质量浓度效应，OTC质量浓度越高，其受到的影响越大，同时，低浓度OTC的影响也会随着时间的延长越来越显著；但是，在长期OTC的选择作用下，微生物群落结构呈现动态变化，出现了适应OTC的新菌群，为活性污泥废水处理效率的回升带来了转机。
Abstract: Oxytetracycline (OTC), a broad-spectrum antibiotic, has been widely used in defense against infectious gram-positive and gram-negative bacteria that are pathogenic to livestock. As a result, OTC can be detected in various effluents, such as livestock wastewater, municipal sewage, and hospital wastewater, as well as their receiving environments. Activated sludge has played an important role in wastewater treatment for nearly one hundred years. However, the pervasiveness of OTC in modern waste streams reduces the viability of microorganisms in activated sludge which are inhibited by OTC. This study was carried out to investigate the interaction between wastewater treatment efficiency and the activity of microbial communities in activated sludge under long-term exposure to OTC. Sequencing batch reactors (SBRs) treating wastewater containing concentrations of 0, 0.1, 5, 20, 60 mg/L OTC were established and studied for 88 days, respectively. All reactors were discharged of effluent every two days and then supplied with a new batch of artificial wastewater. The performance of each reactor was determined by measuring pH, total nitrogen (TN) removal rate and concentration of chemical oxygen demand (COD)  in the effluent. Denaturing gradient gel electrophoresis (DGGE), targeting the V6V7 region of 16S rRNA gene, was applied to analyze the variation in bacterial community structure in the activated sludge as influenced by different concentrations of OTC. Additionally, scanning electron microscopy (SEM) was employed to observe the morphology of activated sludge. Results showed that the wastewater treatment efficiency of activated sludge was inhibited by OTC, especially when OTC concentration was above 20 mg/L. However, treatment efficiency of activated sludge containing OTC would tend to recover in  the course of extended operation time. According to SEM results, richer morphological diversity was observed in R1 (control group without OTC) than in treatment groups (with varying concentrations of OTC) during the course of operation. Filamentous bacteria was only found in R1, and the amount of rod-shaped bacteria decreased while coccus bacteria became more dominant in treatment groups, indicating that rod-shaped bacteria was more sensitive to OTC than coccus bacteria. After operation of SBRs for 88 days, larger round-shaped microorganisms appeared both in R1 and in treatment groups with OTC lower than 60 mg/L. We confer that the microorganisms may be Saccharomycetes, which increased as the concentrations of OTC in the treatment groups increased, except for the group with 20 mg/L OTC. DGGE results indicated that the diversity of microbial community structure was dynamically changed during the procedure and was influenced by the different concentrations of OTC. Compared with R1, the diversity of treatment groups had declined after 88 days, especially for the reactor with 60 mg/L OTC. Sequencing analysis showed that Proteobacteria and Bacteroidetes were the most abundant phyla in all treatment groups and in R1. Different genera belonging to these phyla displayed different resistances to OTC, however, so that the extent to which wastewater treatment efficiency recovered during the course of reactor operation was distinguished by the predominance of unique microbial populations in the treatment groups. It can be concluded that the microbial community structure and wastewater treatment efficiency of activated sludge are  influenced by different concentrations of OTC. The higher the concentration of OTC that is added to treatment groups, the lower the treatment efficiency is. Accumulation of untreated OTC in the low concentration OTC treatment groups may have resulted in an effect of increasing inhibition; however, the microbial community structure varies dynamically and thus the more adaptive species emerges. The emergence of such species may lead to the recovery of wastewater treatment efficiency.  
出版日期: 2013-09-20
CLC:  X 172  
服务　　
把本文推荐给朋友
加入引用管理器
E-mail Alert
RSS
作者相关文章　　
唐璐
牛成镇
吕镇梅*

引用本文:

唐璐， 牛成镇， 吕镇梅*. 土霉素对活性污泥微生物群落结构的影响[J]. 浙江大学学报(农业与生命科学版), 2013, 39(5): 545-555.

TANG Lu, NIU Chengzhen, LYU Zhenmei*. Dynamic change of microbial community structure of activated sludge influenced by oxytetracycline in wastewater. Journal of Zhejiang University (Agriculture and Life Sciences), 2013, 39(5): 545-555.

链接本文:

http://www.zjujournals.com/agr/CN/10.3785/j.issn.1008-9209.2013.03.191    或    http://www.zjujournals.com/agr/CN/Y2013/V39/I5/545

null
No related articles found!