摘要
为探究微量Cu^(2+)对微生物代谢产物及群落结构的影响,采用序批式反应器(SBR),以含Cu^(2+)原水作用下活性污泥为研究对象,分析不同质量浓度Cu^(2+)对胞外聚合物(EPS)和溶解性代谢产物(SMP)的影响,并通过聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术分析总细菌在不同质量浓度微量Cu^(2+)驯化前后的群落结构。结果表明,活性污泥的EPS质量浓度受Cu^(2+)的影响呈波动下降趋势,反应中后期趋于稳定,稳定区间与Cu^(2+)质量浓度成反比。Cu^(2+)加入反应体系后会造成SMP质量浓度短暂下降,随后微生物释放SMP来缓解环境压力,SMP质量浓度有所回升;中后期由于Cu^(2+)积累导致细胞自溶、释放SMP,SMP质量浓度突增,增长幅度与Cu^(2+)质量浓度成正比。不同质量浓度Cu^(2+)会造成特定菌群的消亡,还会促进耐受力强的微生物成为优势菌种。含Cu^(2+)原水会使微生物量和群落多样性降低,当Cu^(2+)质量浓度为3.5 mg/L时SDI由1.92下降至1.23,而由于新优势菌种的产生,Cu^(2+)质量浓度为5.0 mg/L时SDI有所回升。
The given paper intends to explore the effects of the trace Cu2＋ on the active metabolites and the microbial community constitution of biodiversity.For the said purpose,we have taken some activated sludge under the function of the raw water with different concentrations of Cu2＋ as the research object,and analyzed how the various concentrations of Cu2＋ are likely to affect the content of the extracellular polymeric substances（EPS） and the soluble microbial products（SMP） with some SBR.By way of the PCR-based denaturing gradient gel electrophoresis（PCR-DGGE）,we have analyzed the biological community structure of the total bacteria at different concentrations of trace Cu2＋ before and after acclimation.The results of our study indicate that the EPS tends to reveal a fluctuant-decreasing trend under the impact of Cu2＋,which also affects the metabolic activities of the microbial community at the beginning and then tends to lead to a decline of the EPS.And,afterwards,under the influence of Cu2＋,the EPS tends to decline steadily,and,eventually come to a stable interval in the late period in an inverse proportion to the concentration of Cu2＋.Moreover,adding Cu2＋ to the reaction system may result in a transient decrease of SMP,leading to the reaction of the bacteria to the harsh environment.And,later,the final accumulation of Cu2＋ may lead to the cellular autolysis and promote the actual release of the SMP.Nevertheless,there may come about a sharp increase of SMP,in which the growth rate turns to be proportional to the concentration of Cu2＋.When the different Cu2＋ concentrations result in the demise of the particular bacteria in the activated sludge,it would be possible to promote the growth of some special microorganisms,even turning them into the dominant flora.The addition of Cu2＋ would lead to a temporary reduction of the amount of biological diversity,because the mixed liquid suspended solids（MLSS） may also decline in different degrees,thus affecting the diversity of the microbial populations,with SDI dropping from 1.92 to 1.23 when the Cu2＋ concentration is 3.5 mg/L,and then tends to increase when the Cu2＋ concentration becomes 5 mg/L because the new dominant flora grew up in the condition when the mechanism of the changes of microbial biodiversity under different Cu2＋ concentrations turned to be a bit more complicated.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2015年第6期265-268,共4页
Journal of Safety and Environment
基金
天津市自然科学基金项目(07JCZDJC02100)
