安徽某铁矿不同矿山废水库中微生物群落结构特征

Microbial community structure characteristics in different mine drainage lakes of an iron mine in Anhui Province

摘要:

[目的]研究安徽某铁矿不同矿山废水库中微生物群落结构特征及其影响因素。[方法]对比分析了该铁矿3个大型废水库的地球化学特征，并用高通量测序技术研究了水体中微生物群落组成，进而用统计学方法解析了环境因子对微生物群落结构的影响。[结果]3个废水库中有2个为酸性，1个为中性，理化性质有明显的差异。近年形成的塌方采场废水库（TF）pH仅为2.55±0.01，Fe浓度高达154.95±0.78 mg/L，SO₄^2-浓度为3374.86±3.81 mg/L；形成于20世纪70年代的排土场废水库（PT）酸性略弱（pH 2.9±0.02），Fe浓度（34.57±4.00 mg/L）与TF相比明显降低，SO₄^2-浓度则高达10398.98±626.70 mg/L；东沙采场废水库（DS）则为中性（pH 7.55），但SO₄^2-仍高达4162.99 mg/L，主要的金属离子为Mg（594.90 mg/L）、Ca（650.10 mg/L）。3个废水库的原核生物多样性随pH的升高而升高。两个酸性废水库的原核生物组成较为接近，但TF的化能自养菌含量较高（69.54%±2.89%），PT的化能异养菌含量较高（64.45%±13.81%）。自养铁氧化菌Ferrovum在TF中的比例高达（64.17±1.84）%，在PT中则下降为（35.39±13.74）%。但PT中含有丰富的化能异养嗜酸菌如Acidicapsa（15.75%±3.99%）、Acidiphilium（10.65%±2.05%）、Acidisphaera（6.34%±1.02%）等。DS中虽然也含有较高的金属离子和SO₄^2-，但其中的原核生物组成与TF和PT截然不同，主要为Limnohabitans（18.47%）、Rhodobacter（8.42%）等。3个废水库的真核生物群落主要由藻类组成，酸水库TF和PT中主要为棕鞭藻属（Ochromonas）和胶球藻属（Coccomyxa），棕鞭藻属在TF中（53.65%±2.02%）占优势，胶球藻属在PT中（68.84±10.4%）占优势，中性废水库DS中则主要是小环藻属（Cyclotella）（49.85%）。经统计学分析，pH是影响矿山废水微生物多样性和群落组成的主要环境因素。

Abstract:

[Objective] To study the prokaryotic and eukaryotic community structure and the physicochemical factors influencing their distribution in three mine wastewater lakes from a pyrite mine in Anhui Province. [Methods] Geochemical analysis characteristics of three wastewater lakes were measured, and microbial community compositions of the lakes were studied using high-throughput sequencing. The relationship between microbial community structure and environmental factors was also analyzed based on statistical methods. [Results] Samples from three wastewater lakes included two acidic and one neutral, with significant differences in physicochemical properties. Lake TF, typically acidic, formed about 5 years ago and is characterized by low pH (2.55±0.01), Fe (154.95±0.78 mg/L) and SO₄^2- (3374.86±3.81 mg/L). Lake PT is also acidic, pH (2.9±0.02), however, it formed in the 1970's, and has significantly lower Fe (34.57±4.00 mg/L) and higher SO₄^2- (10398.98±626.70 mg/L) than lake TF. Lake DS is neutral (freshwater), characterized by pH (7.55), high content of SO₄^2- (4162.99 mg/L), while other main metal ions detected were Mg (594.90 mg/L) and Ca (650.10 mg/L). It was observed that the prokaryotic biodiversity of the three wastewater lakes generally increased with increasing pH. The prokaryotic composition of the two acidic wastewater lakes was relatively close. However, lake TF was dominated by autotrophic iron oxidizing bacteria (69.54%±2.89%), while lake PT by heterotrophic bacteria (64.45%±13.81%). The ratio of autotrophic iron oxidizing bacteria Ferrovum in TF was (64.17±1.84)%, and it decreased to (35.39±13.74)% in PT. However, heterotrophic bacteria were abundant in PT as observed by the distribution of Acidicapsa (15.75%±3.99%), Acidiphilium (10.65%±2.05%), and Acidisphaera (6.34%±1.02%). Lake DS had a typically distinct microbial community compared to acid lakes (TF and PT) despite of a high content SO₄^2-. Lake DS had an abundance of Limnohabitans (18.47%) and Rhodobacter (8.42%). The eukaryotic community of three wastewater lakes was mainly composed of algae. The acidic lakes (TF and PT) were mainly populated by Ochromonas and Coccomyxa, accounting for (53.65%±2.02%) in TF and (68.84%±10.4%) in PT respectively. Lake DS was mainly characterized by Cyclotella (49.85%). From our analyses of physicochemical factors, we found that pH was the main factor affecting microbial community composition in acidic wastewater lakes.