Effects of lead pollution on soil microbial community diversity and biomass and on invertase activity

Abstract

Lead (Pb) pollution is one of the most widespread and harmful environmental problems worldwide. Determination of changes in soil properties and microbial functional diversity due to land use is needed to establish a basis for remediation of soil pollution. This study aimed to investigate soils contaminated by Pb from different sources and to analyze the functional diversity and metabolism of soil microbial communities using Biolog technology. Pb pollution (>300 mg kg−1) significantly influenced the diversity and metabolic functions of soil microbial communities. Specifically, Pb contamination significantly reduced soil microbial biomass carbon (C) and nitrogen (N) levels and catalase activity while increasing invertase activity. Furthermore, Biolog EcoPlate assays revealed that Pb pollution reduced the general activities of soil microorganisms, suppressing their ability to utilize C sources. In Pb-contaminated areas lacking vegetation cover, Shannon, Simpson, and McIntosh diversity indices of soil microorganisms were significantly reduced. The microbial diversity and biomass C and N levels were affected by land use and soil properties, respectively, whereas soil enzyme activity was primarily affected by the interaction between land use and soil properties. Our results provide a reference and a theoretical basis for developing soil quality evaluation and remediation strategies.