鄂尔多斯遗鸥国家级自然保护区桃-阿海子浮游细菌多样性及其与水体重金属浓度的关联性分析

Diversity of Planktonic Bacteria and Its Correlation with Heavy Metal Concentration in T-A Nur in Erdos Relic Gull National Nature Reserve

桃-阿海子是遗鸥(Larus relictus)重要繁殖地,一度趋于干涸,为保护该重要湿地及其中繁殖和迁徙的珍稀鸟类,当地政府启动引黄工程进行补水,所补水为矿井水,矿井水中通常含有大量重金属,重金属又会对水体微生物产生影响,微生物是湖泊生态系统的重要驱动者,且对于生存其中的鸟类具有重要影响。所以为评估所补矿井水对当地生态系统及珍稀候鸟的影响,本研究通过16S rRNA高通量测序的方法分析了鄂尔多斯遗鸥国家级自然保护区桃-阿海子引黄工程注水口1(ZSK1)、注水口2(ZSK2)、湖边(HB)和湖心岛(HXD)4个区域的水样样本中浮游细菌的多样性,并对其与水体重金属元素含量进行关联性分析。结果显示ZSK1和ZSK2水样样本中微生物不存在显著差异,HB和HXD水样样本中微生物多样性不存在显著差异,而ZSK与HB和HXD样本中微生物多样性存在显著差异。微生物群落组成分析发现这几个区域的主要细菌门是变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)、疣微菌门(Verrucomicrobiota)和放线菌门(Actinobacteria),在属水平存在着大量的未知微生物。该区域不同采样点水样中重金属元素含量存在差异,并驱动了微生物群落的构建过程,显著影响4个采样点微生物群落结构的环境变量依次为Pb、Cr和Ni。在HB和HXD样本中耐受重金属的细菌丰度高一些,而在ZSK样本中其丰度较低。该结果对于评估和预测重金属污染等人为活动对微生物群落的影响具有重要意义,并将为鄂尔多斯遗鸥国家级自然保护区桃-阿海子生态环境管理和污染防治提供重要参考,同时为珍稀野生动物保护提供依据。

T-A Nur,which once tended to dry up,is an important breeding ground for Relict Gull(Larusrelictus).In order to protect this important wetland where the rare birds breed and migrate,the local government initiated a programme named“Yellow River Diversion Project”to replenish water to this wetland.The supplemented water originated from mine water that usually contains a large amount of heavy metals,which will have an impact on wa-ter microorganisms.Microorganisms are important drivers of lake ecosystems,and simultaneously affects the birds living here significantly.In order to evaluate the impact of the supplemented mine water on the local ecosystem and rare migratory birds,this study analyzed the planktonic bacteria in the water samples from four areas including the water injection port 1(ZSK1),water injection port 2(ZSK2),the lakeside(HB)and the lake island(HXD),and then the relationship between microbial community and heavy metal concentration was carried out with correlation analysis.The results showed that there was no significant difference in the microbial diversity in the water samples from ZSK1 and ZSK2,as well as the water samples from HB and HXD.However,there were significant differ-ences in microbial diversity between the samples from ZSK and the HB or HXD.Analysis of microbial community composition showed that the main bacterial phyla in these regions were Proteobacteria,Bacteroidetes,Firmicutes,Verrucomicrobiota and Actinobacteria.A large number of unknown microorganisms exist at the genus level.The different levels of heavy metals in different sampling points in this region drive the emergence of differences in mi-crobial community composition.The environmental variables that significantly affected the microbial community structure of the four sampling points were Pb,Cr and Ni in order.Heavy metal-tolerant bacteria were more abun-dant in HB and HXD samples,but lower in ZSK samples.The results are of great significance for evaluating and predicting the impact of anthropogenic activities such as heavy metal pollution on microbial communities.In addi-tion,these data also provide an important reference for the ecological management and pollution prevention in the T-A Nur wetland,Ordos Relic Gull National Nature Reserve,meanwhile to protect the rare species living in it.