Bacterial compatibility and immobilization with biochar improved tebuconazole degradation, soil microbiome composition and functioning

Abstract

Tebuconazole is a widely used fungicide that may impair soil health. Presently, limited information is available on the bioremediation of tebuconazole-contaminated soil using biochar as a carrier for bacteria. In this study, we firstly isolated a tebuconazole-degrading strain and identified it as Alcaligenes faecalis WZ-2. Then, we used wheat straw-derived biochar as carrier to capture strain WZ-2 to assemble microorganism-immobilized composite. Finally, we investigated the effects of strain WZ-2 and biochar-immobilized WZ-2 on tebuconazole biodegradation, microbial enzyme activities and community composition in the contaminated soil. Results showed that, as compared to control, the strain WZ-2 and biochar-immobilized WZ-2 accelerated the degradation of tebuconazole, while reducing the half-life of tebuconazole from 40.8 to 18.7 and 13.3 days in soil, respectively. However, biochar alone than control slightly retarded the degradation of tebuconazole in soil. Though tebuconazole (10 mg/kg) negatively affected the soil enzyme activities (urease, dehydrogenase, and invertase) and microbiome community structure, the biochar-immobilized WZ-2 not only accelerated the degradation of tebuconazole but also restored native soil microbial enzyme activities and microbiome community composition. Our results suggest that a compatible combination of bacteria with biochar is an attractive and efficient approach for remediation of pesticide-contaminated soil and improvement of soil biological health.

Keywords: Alcaligenes faecalisWZ-2; Bioremediation; Immobilization; Soil microbiome; Tebuconazole.