云南省蒙自酸性矿山排水微生物群落结构和功能

Microbial community structure and function in acid mine drainage from Mengzi, Yunnan Province

摘要:

为探究酸性矿山排水生态系统不同环境中的微生物群落和功能，全面了解酸性矿山排水的形成和发展规律，采用高通量测序技术研究云南省蒙自某矿区酸矿水坑和周边溪水中的原核微生物群落组成，并结合样本理化特征分析影响群落结构的主要因素，进而解析菌群的环境功能。研究发现酸矿水坑中主要有广古菌门、变形菌门 (包括α、γ和δ变形菌纲)、硝化螺菌门、厚壁菌门、放线菌门和酸杆菌门等类群，与周边溪水的群落结构具有明显差异。群落多样性与pH呈显著正相关，而热原体纲 (Thermoplasmata) 与pH呈负相关，可对群落结构起主导作用。酸矿水坑不同样本中均具有高丰度的亚铁原体属Ferroplasma (6.60%–86.34%)，酸硫杆菌属Acidithiobacillus是酸矿水和沉积泥中主要的铁、硫氧化细菌，而专性铁氧化的钩端螺旋菌属Leptospirillum的丰度较低，铁卵形菌属Ferrovum几乎只存在于酸矿水中；此外，嗜酸或耐酸的异养菌广泛分布于酸矿水和沉积泥中，它们可促进铁、硫氧化菌的生长及催化矿石溶解。结果表明，pH通过影响微生物多样性和菌群分布而对酸性矿山排水环境微生物群落结构造成重大影响。

Abstract:

In order to explore the microbial communities and functions in distinct environments of acid mine drainage (AMD) ecosystem and fully comprehend the patterns of AMD formation and development, high-throughput sequencing technology was used to study the prokaryotic community composition in AMD puddles and surrounding rills in a mining area in Mengzi, Yunnan Province, China. By combining with physicochemical properties of the samples, we distinguished the key factors affecting the community structure and analyzed the environmental functions of the microflora. We discovered that the main phyla in AMD puddles were Euryarchaeota, Proteobacteria (including the class α-, γ- and δ-Proteobacteria), Nitrospirae, Firmicutes, Actinobacteria, and Acidobacteria. Community structure of the AMD puddles apparently differed from that of the surrounding rills. Microbial diversity was significantly positively correlated with pH, whereas the relative abundance of Thermoplasmata was negatively correlated with pH and this class might play a predominant role in community structure. There was high relative abundance of the genus Ferroplasma (6.60%–86.34%) in different samples of AMD puddles. Acidithiobacillus spp. were the major iron- and/or sulfur-oxidizing bacteria in AMD solutions and sediments, whereas relative abundance of the obligate iron-oxidizer Leptospirillum spp. was lower, and Ferrovum spp. were almost only present in the AMD solutions. In addition, acidophilic or acid-tolerant heterotrophic bacteria were widely distributed in the AMD solutions and sediments, which might promote the growth of iron- and/or sulfur-oxidizers and catalyze the oxidative/reductive dissolution of metal ores. Our results suggested that pH significantly impacted the microbial community structure of AMD environment by affecting the microbial diversity and microflora distribution.