Screening and Characteristics of Cadmium-Tolerant Microorganisms in Soil Remediation

Cadmium (Cd) pollution of soil is a severe environmental problem. Bioremediation of Cd-contaminated soil is an environmentally friendly and low-cost remediation method. In this work, three Cd-tolerant fungi strains, named L1, L2, and L3, were screened and domesticated. The adsorption characterization and the remediation effect of the three strains were investigated. The results show that the adsorption efficiency (AE) of Cd by the three strains reached 83.6%,73.1% and 57.1%, respectively. Scanning electron microscopy (SEM) revealed that the surface of Cd-tolerant fungus (L1) is rough, with many indents and excellent Cd adsorption sites. The prepared microbial agents reduced the exchangeable Cd content and increased other Cd contents in highly Cd-contaminated soil. In addition, the number of microorganisms and the activities of catalase and urease in the soil were also improved. The screened fungi have the remediation abilities for Cd-contaminated soil. This work aims to investigate the remediation mechanism and effect of Cd-tolerant microorganism on Cd-contaminated soil, and provide a theoretical basis for practical application.