Globally, heavy metal (HM) pollution of soil is a serious problem that can lead to long-term toxic effects on soil. In this milieu, the present study investigated the eco-toxicological effects of three trace elements, e.g., cadmium (Cd), copper (Cu), and lead (Pb), on enzyme activities and microbial function and structural diversity in phaeozem and red soil samples. Hormesis effects of Cd, Cu, and Pb on catalase and invertase activities were observed in phaeozem soil, while for red soil, there was an inhibitory effect on the activities of catalase and invertase under Cu- and Pb-contaminated soils. The utilization of carbon sources was inhibited in Cd- and Pb-treated phaeozem soil, but higher utilization of polymers and amines exhibited in Cu-contaminated soil. Although the substrates under the contamination of Cd, Cu, and Pb had high average well color development values across incubation time, the utilization of various substrates did not exhibit a regular trend under different treatments with HMs. The denaturing gradient gel electrophoresis (DGGE) analysis showed that the HMs led to marginal changes in the number and species of soil microbes, while the similarity indices decreased in HM-treated samples, varying from 66.2 to 77.3% in phaeozem soil and from 62.8 to 66.7% in red soil. However, the sequence analysis showed that there existed metal-resistant microbial communities such as Bacillales, Bacillus, and Massilia and so on under the stress of HMs.

中文翻译：

---

重金属污染土壤中酶活性，底物利用方式和微生物群落多样性的变化

在全球范围内，土壤的重金属（HM）污染是一个严重的问题，可能导致对土壤的长期毒性作用。在此环境中，本研究调查了镉（Cd），铜（Cu）和铅（Pb）等三种微量元素对phaeozem和红壤中酶活性，微生物功能和结构多样性的生态毒理作用样品。在Phasezem土壤中观察到Cd，Cu和Pb对过氧化氢酶和转化酶活性的兴奋作用，而对于红壤，在Cu和Pb污染的土壤中对过氧化氢酶和转化酶的活性具有抑制作用。在Cd和Pb处理的phaeozem土壤中碳源的利用受到抑制，但是在Cu污染的土壤中却表现出更高的聚合物和胺利用率。尽管底材受到Cd，Cu，并且Pb在整个孵育时间内具有较高的平均显色值，在不同的HMs处理下，各种底物的利用没有呈现规律的趋势。变性梯度凝胶电泳（DGGE）分析表明，HMs导致土壤微生物数量和种类的边际变化，而HM处理样品的相似性指数下降，在phaeozem土壤中相似性指数从66.2％降低到77.3％，从62.8％降低到62.8％。在红壤中占66.7％。然而，序列分析表明，存在金属抗性微生物群落，例如 变性梯度凝胶电泳（DGGE）分析表明，HMs导致土壤微生物数量和种类的边际变化，而HM处理样品的相似性指数下降，在phaeozem土壤中相似性指数从66.2％降低到77.3％，从62.8％降低到62.8％。在红色土壤中占66.7％。然而，序列分析表明，存在金属抗性微生物群落，例如 变性梯度凝胶电泳（DGGE）分析表明，HMs导致土壤微生物数量和种类的边际变化，而HM处理样品的相似性指数下降，在phaeozem土壤中相似性指数从66.2％降低到77.3％，从62.8％降低到62.8％。在红色土壤中占66.7％。然而，序列分析表明，存在金属抗性微生物群落，例如在HMs的压力下，芽孢杆菌，芽孢杆菌和马西利亚等。