【摘要】 构建6个池塘型微宇宙模拟水生态系统,1个设为对照组,试验组连续投加次氯酸钠13d,投加剂量分别为1.0、2.5、5.0、10.0、20.0mg/L,停止投加后再观察10d.试验期间对各微宇宙分别进行8次采样,经37℃培养后提取细菌总DNA,进行16SrDNAV3区扩增后,对扩增产物进行TGGE分析.对TGGE图谱中的主要条带进行回收、重新扩增、克隆、建库、测序以及序列分析.结果显示,消毒剂进入环境后会对细菌群落结构产生影响,但不同剂量消毒剂产生的影响有显著差异,存在明显的剂量-效应关系:低剂量消毒剂对细菌群落结构的影响比较小,而且是可逆的,微宇宙系统对消毒剂逐渐适应后其群落结构即可恢复;而高剂量消毒剂对细菌群落结构的破坏比较大,且不可逆转,即使消毒剂停止投加后也不能恢复.说明盲目的过量投加消毒剂会对水体微生态环境造成严重破坏.图4表1参10更多还原

【Abstract】 Six pond microcosms were constructed to simulate aquatic ecosystems, including one as control. Sodium hypochlorite was added to five experimental microcosms every 24 hours for 13 consecutive days, and then the microcosms were observed for 10 days. The doses of sodium hypochlorite added were 1.0 mg/L, 2.5 mg/L, 5.0 mg/L, 10.0 mg/L and 20.0 mg/L, respectively. Water samples were collected from each microcosm for 8 times during the experiment. All the samples were incubated at 37 ℃ and the total genomic DNA of bacteria was extracted. The 16S rDNA V3 region fragments were amplified from the total DNA and TGGE analysis of 16S rDNA V3 region was conducted. Several major bands from TGGE profiles were recovered from gel, the recoved DNA was reamplified and cloned, and libraries were constructed. Four clones were picked from each library and sent to invitrogen (Shanghai) for sequencing. Sequence analysis was performed to study the polymorphism of TGGE bands and diversity of bacterial community in the microcosms. These results indicated that disinfectant would affect bacterial community structure in environment, but the effects caused by disinfectant in different doses varied markedly. There was a clear dose-effect relationship between disinfectant doses and bacterial community change in the microcosms. The effects of disinfectant at low doses on bacterial community structure were limited and reversible. After microcosm system was gradually adapted to disinfectant, the community structure would be recovered. However, the destructions of disinfectant at high doses to bacterial community structure were severe and irreversible. The community structure would be impossible to recover even if the addition of disinfectant was stopped. All the above suggested that blind and excessive application of disinfectant would destroy microbial ecology in environment severely. Fig 4, Tab 1, Ref 10更多还原