安徽省某酸性矿山废水坑湖中细菌群落的垂向分布特征及其影响因素

Vertical spatial distribution of bacteria in a pit lake affected by acid mine drainage in Anhui Province and its influencing factors

摘要:

【目的】探究酸性矿山废水(acid mine drainage，AMD)坑湖中细菌群落沿垂向不同水深的分布规律及与环境因子之间的相互作用。【方法】采用16S rRNA基因高通量测序技术，对安徽省某AMD坑湖中6条采样垂线不同水深深度的细菌群落进行调查，同时测定水质理化指标，使用统计学软件分析细菌和地化参数间的联系。【结果】AMD坑湖中水质特征及细菌群落结构出现明显分层现象，自上而下溶解氧降低而pH和多种金属离子浓度增加，微生物群落结构发生变化，多样性和部分物种的丰度增大。细菌群落组成上，表层水域以Proteobacteria (Alpha、Gammaproteobacteria)和Acidobacteria占据主导地位；中下层水域则由Firmicutes、Acidobacteria、Actinobacteria、Gammaproteobacteria和Patescibacteria等共同主导。统计分析结果表明，TN、DO、ORP、pH、Fe、Mn、Al和Zn与嗜酸细菌丰度显著相关，是细菌空间分布的主要限制因素。【结论】AMD坑湖中水质理化特征和细菌群落分布在垂向空间上存在显著差异，群落的垂向分层特征是由多种环境因子共同作用下的结果。本研究对深入了解AMD的微生物分布规律及对AMD的原位生物修复和治理具有参考价值。

关键词:酸性矿山废水;酸性坑湖;垂向分布;细菌群落;环境梯度

Abstract:

[Objective] The purpose of this paper is to explore the distribution of bacterial communities along different water depths in a pit lake affected by acid mine drainage (AMD) and its relationship with environmental factors. [Methods] The 16S rRNA gene high-throughput sequencing technology was used to investigate the bacterial communities along different water depths at 6 sampling sites in the lake. The physicochemical indexes of water quality were measured at the same time. The relationship between bacterial distribution and water physicochemical indexes was analyzed by statistical software. [Results] The physicochemical properties and bacterial distribution showed obvious stratification. Dissolved oxygen (DO) decreased while pH and concentrations of metal ions increased from top to bottom. Meanwhile, the bacterial diversity and the abundance of some species increased from top to bottom. Proteobacteria (Alpha, Gammaproteobacteria) and Acidobacteria were dominated in the surface water, while Firmicutes, Acidobacteria,Actinobacteria, Gammaproteobacteria and Patescibacteria were rich in the middle- and deep-layer water. The total nitrogen (TN), DO, oxidation-reduction potential (ORP), pH, Fe, Mn, Al and Zn were significantly correlated with the abundance of acidophilic bacteria, which were the main factors influencing the spatial distribution of bacteria. [Conclusion] The distribution of bacteria in the pit lake affected by AMD showed an obvious vertical pattern, which was caused by the joint action of various environmental factors. This study has reference value for understanding the microbial distribution in the AMD-influencing pit lake and in situ bioremediation of AMD.

Key words:acid mine drainage;pit lake;vertical distribution;bacterial community;environmental gradient