硝基苯废水驯化过程中细菌群落结构的变化

Change of bacterial community structure acclimated by nitrobenzene-containing wastewater

采用PCR-DGGE和RAPD分子标记技术分析了不同浓度硝基苯废水驯化的细菌群落结构变化,探讨硝基苯废水对细菌群落结构及多样性的影响.结果表明:RAPD分子标记显示不同浓度废水驯化的细菌群落的Neis指数(h)平均为0.2523,Shannons信息指数(I)平均为0.3730;而采用DGGE技术得到不同浓度废水驯化的细菌群落的h平均为0.2523,I平均为0.3958.RAPD分子标记分析可知当废水浓度从0%增高至10%时,多样性指数增加,而当浓度继续升高,多样性指数逐渐下降;DGGE方法分析发现当废水浓度从0%升高至60%时,多样性指数逐渐下降,但当废水浓度达到80%时,多样性指数比60%时略有升高.基于DGGE数据分析获得的Shannon-Wiener多样性指数、Simpson多样性指数和丰富度指数与COD、Cl-及硝基苯浓度之间均相关极显著,表明废水中所含的硝基苯、有机物及氯离子含量是引起细菌群落结构改变的主要原因.利用RAPD和DGGE两种方法得到的不同浓度硝基苯废水驯化的细菌群落相互之间的平均遗传距离分别为0.5717和0.4700.不同浓度硝基苯废水驯化获得的细菌群落可分为两大组,一组包括高浓度(60%和80%)废水驯化细菌,另一组为低浓度(0%、5%、10%、20%和40%)废水驯化细菌.

PCR-DGGE and RAPD molecular markers were used to analyze the changes of bacterial community struc- ture acclimated by nitrobenzene-containing wastewater in order to explore the mechanism how nitrobenzene- containing wastewater influence bacterial communities structure and diversity. Based on RAPD data, Nei＇s gene di- versity index averaged 0. 252 3 and Shannon＇s information index averaged 0. 373 0, while Nei＇s gene diversity index averaged 0. 252 3 and Shannon＇s informative index averaged 0. 395 8 based on DGGE data. Based on RAPD data, the diversity increased when the concentration increased from 0% to 10 %, and then decreased when the concentration increased from 10% to 80%, But based on DGGE data, the diversity increased when the concentration increased from 0 % to 60 % and increased when the concentration increased to 80 %. Shannon-Wiener diversity index, Simpson diversity index and Richness index based on DGGE data was extremely significant correlated with the concentration of COD, Cl- and nitrobenzene, indicating that different concentration of COD, Cl , nitrobenzene might be the main factor that induce the changes of bacterial community structure. The genetic distance among bacteria communities acclimated by different concentration of nitrobenzene-containing wastewater averaged 0. 571 7 and 0. 470 0, respec- tively, when RAPD and DGGE methods were used. Clustering results showed that bacteria communities acclimated by 60% and 80% wastewater were clustered together into one group and the other bacteria communities acclimated by low content wastewater （0 %, 5 %, 10 %, 200% and 40 % ） were clustered together into another group.