锌离子对活性污泥微生物DNA序列多样性的影响

研究了锌离子对活性污泥微生物群落结构的影响.不同浓度的锌离子对有机物的降解和氮的转化均有抑制.经过驯化后,处理系统对有机物的降解可以逐步得到恢复,而对于氨氮和亚硝酸氮的降解则并不随着驯化时间的延长而得到改善.随机扩增多态性RAPD分析表明,在不同的驯化阶段,DNA序列的分子多样性是不同的.结果显示,加入锌离子的微生物多样性明显小于对照组,驯化成熟的实验组尽管在COD的去除率上和对照组没有什么差别,但在生物多样性、丰富度、均匀度和相似性上与驯化初期有较大的差别.从RAPD条带上可清楚地看到某些细菌的消失,以及耐受锌离子的种类的持续存活. 

The Effect of Zinc Ions on Activated Sludge Microbes and Its DNA Sequence Diversity Analysis

The authors investigated the effects of zinc ion on the community structure of activated sludge microbes.Zinc ion of different concentrations can inhibit the degradation of organic compounds and transformation of nitrogen.After acclimation,the degradation of the organics by the treatment system can be gradually recovered,but the degradation of ammonia nitrogen and nitrite nitrogen can hardly be improved after extension of acclimation time.The change of diversity and similarity of bacterial community acclimated by zinc were analyzed by random amplified polymorphism DNA (RAPD).The results showed that DNA sequence diversities were different during procedures of acclimation.The diversity of zinc loading unit was lower than that of the control one.There existed much difference in diversity,richness,evenness and similarity between the end and the beginning of the acclimation although the COD removal rate reached the same at the end of acclimation.It could be clearly seen that some bacteria disappeared while some zinc ion tolerated species survived from the RAPD fingerprint.