铜矿重金属污染对土壤微生物群落多样性和酶活力的影响

The Impact of Heavy Metal Contamination on Soil Microbial Diversity and Enzyme Activities in A Copper Mine

重金属污染导致土壤环境质量的恶化,而土壤微生物的群落多样性和土壤酶活力是评估污染程度的重要指标。该研究选择了安徽铜陵铜矿附近受重金属复合污染的4个土壤样本,评估和比较了样本中5种重金属(砷、镉、锌、铅和铜)的污染程度;研究和分析了土壤细菌和真菌群落的多样性以及土壤酶活力。结果表明,(1)从样本S1到S4,综合污染指数分别为0.71、3.85、4.37和8.47;S1样本尚未受到重金属污染,而S2、S3和S4样本受到不同程度重金属砷、镉、锌和铜的污染;以镉污染为主,不存在铅污染。(2)从样本S1到S4,随着综合污染程度的增加,土壤中脲酶、磷酸酶和脱氢酶的酶活力均呈现降低的趋势,且磷酸酶和脱氢酶的酶活力与镉、锌和铅的浓度呈显著负相关,而脲酶酶活力与重金属浓度没有明显的相关性。(3)随着综合污染指数的上升,细菌和真菌群落的多样性均下降,且真菌群落物种丰富度的变化明显于细菌。该研究对矿区土壤重金属生物治理及环境修复具有重要意义。

Contamination of heavy metals results in deterioration of soil health, which can be assessed by the diversity of microbial community and the activity of soil enzymes. In this study, four soil samples were collected from a copper mine in Tongling City of China, and were further analyzed for evaluating the contamination of five metals (arsenic, cadmium, zinc, lead and copper), the diversity of bacteria and fungi as well as the activity of soil enzymes. Our results indicated that: (1) the comprehensive pollution index was 0.71, 3.85, 4.37 and 8.47 for sample 1 to 4 (S1~S4), respectively, indicating that S1 was uncontaminated while S2, S3 and S4 were contaminated to different extent; cadmium was the main metal while no lead was detected in four samples; (2) the activity of urease, phosphatase and dehydrogenase decreased with the increase of the comprehensive pollution index of four samples; the activity of phosphatase and dehydrogenase was negatively correlated to the concentration of cadmium, zinc and lead, while the urease activity showed no significant correlation with these metals; (3) the diversity of bacteria and fungi decreased with the increase of the comprehensive pollution index, and the change of fungi abundance was more obvious than that of bacteria. This study will contribute to the bioremediation of heavy metal contamination in mining areas.