类固醇雌激素对土壤包气带微生物群落变化研究

发布时间：2018-01-22 07:51

本文关键词： 类固醇雌激素土壤包气带 PCR-DGGE 微生物群落变化　出处：《沈阳大学》2017年硕士论文　论文类型：学位论文

【摘要】：类固醇雌激素(Steroidal Estrogens,SEs)作为一类新兴环境污染物,具有来源广、态性多、浓度低、毒性高等特性,在国内外的水土环境中均被频繁检出。环境中SEs的主要来源是污水处理厂和畜禽养殖场。本文选择具有代表性的种植业农田包气带土壤沈阳市沈北新区新城堡四村某以家禽粪便为有机肥的玉米地包气带土壤,畜牧业包气带土壤沈阳市辽中县肖寨门镇某畜禽养殖场厂区包气带土壤,类固醇污染的农田土壤作为三个主要研究对象,通过PCR-DGGE指纹分析技术对土壤包气带内微生物群落的特征进行时空动态分析。本文的主要结论如下:1、不同深度下玉米地和畜牧场包气带土壤样品的戴斯系数(Cs)和细菌种群的多样性指数(H’)、丰富度(S)和均匀度(E)整体都呈现下降趋势。在下降过程中都不断的上下波动,戴斯系数的上下变动范围不大,多样性指数等波动比较剧烈。沈北玉米地土壤样品深度由2.0 m到2.8 m变动和由6.8 m到7.6 m变动时,其Cs、H’、S、E都明显上涨;辽中畜牧养殖场土壤样品深度由0.4 m到0.5 m变动和由2.3 m到2.5 m变动时,其Cs、H’、S、E都明显下降。这些变动可能是由相应土壤深度下雌激素的含量与种类的变动和土壤主要组成成分的变动共同作用下造成的。2、不同浓度17β-E2、E1,不同暴露时间下土壤样品的Cs与细菌种群的多样性指数、丰富度及均匀度各不相同。在暴露时间内,农田土壤中添加的E1浓度为500 ng/kg时,Cs总体平缓降低,但其多样性整体呈增长趋势。在暴露时间内,17β-E2浓度为300 ng/kg的Cs整体呈平缓上升趋势,其多样性总体呈逐步增长趋势。对比不同暴露时间不同污染物浓度下微生物的多样性发现,在一定范围内,微生物群落多样性随着E1浓度的增加而减小,超过某一值时其多样性则会迅速增加,继续增大E1浓度,多样性增加趋势逐渐缓慢。在一定范围内,微生物群落多样性随着17β-E2浓度的增加而增大,超过一定值其多样性则会受到抑制,随着暴露时间的推移,抑制作用在降低。造成这种结果的原因可能是,新适应性物种的出现打破这种抑制作用,抗SEs和能够有效降解SEs的微生物可以在SEs污染土壤中富集。E1可以转变为E2、E3和E1-3G,E2可以在转变为E1、E3、E2-3G和E1-3G,这种互相转变也会给微生物菌群多样性带来更为复杂的变化。
[Abstract]:As a new class of environmental pollutants, steroid estrogen strogensor (SES) has a wide range of sources, many states, low concentration, high toxicity and so on. The main sources of SEs in the environment are sewage treatment plants and livestock and poultry farms. A cornfield aerated soil with poultry manure as organic fertilizer was found in the fourth village of Xincastle, Shenyang, Shenyang. Soil in aeration zone of animal husbandry in Liaozhong county, Shenyang, China. The soil in aeration zone of a livestock and poultry farm in Shaozhaimen Town, Shenyang City was studied. Steroid contaminated farmland soil was taken as the three main research objects. The characteristics of microbial community in soil aeration zone were analyzed by PCR-DGGE fingerprinting technique. The main conclusions of this paper are as follows: 1. At different depths, the soil samples in cornfields and livestock pastures were measured by the Deiss coefficient (CSS) and the diversity index of bacterial population (HN). The richness (S) and evenness (E) of the whole show a downward trend. In the process of decline, the fluctuation is constant, and the range of the Deiss coefficient is not large. When the depth of soil samples varied from 2.0 m to 2.8 m and from 6.8 m to 7.6 m in the maize field in Shenbei, the soil samples had a significant variation in their CSN HN S. E. When the depth of soil samples varied from 0.4 m to 0.5 m and from 2.3 m to 2.5 m in the livestock breeding farm in central Liaoning Province, the soil samples were found to be of CSH. These changes may be caused by the changes of estrogen content and species under the corresponding soil depth and the changes of the main components of soil. The changes of 17 尾 -E2 at different concentrations may be caused by the changes of E and E contents. Under different exposure time, the diversity index, richness and evenness of soil samples and bacterial populations were different under different exposure time. When the concentration of E1 in farmland soil was 500 ng/kg, the total content of FCs decreased slightly, but the diversity of them increased gradually, and the diversity increased during the exposure time. The concentration of 17 尾 -E2 was 300 ng/kg. Compared with different exposure time and concentration of pollutants, the diversity of microbial community decreased with the increase of E1 concentration in a certain range. Over a certain value, the diversity will increase rapidly, and continue to increase the concentration of E1, the diversity will gradually increase slowly. In a certain range, the diversity of microbial communities increases with the increase of 17 尾 -E2 concentration. Beyond a certain value, its diversity is inhibited, and the inhibition decreases as exposure time goes on. The reason for this may be that the emergence of new adaptive species breaks this inhibition. The microorganisms resistant to SEs and capable of effectively degrading SEs can enrich. E1 in SEs contaminated soil can be transformed into E2C E3 and E1-3GN E2 can be transformed into E1N E3. E2-3G and E1-3G, this mutual transformation will also bring more complex changes in microbial diversity.
【学位授予单位】：沈阳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X592;X53

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