Effects of Zeolite and Biochar Addition on Ammonia-Oxidizing Bacteria and Ammonia-Oxidizing Archaea Communities during Agricultural Waste Composting

Abstract

The effects of zeolite and biochar addition on ammonia-oxidizing bacteria (AOB) and archaea (AOA) communities during agricultural waste composting were determined in this study. Four treatments were conducted as follows: Treatment A as the control with no additive, Treatment B with 5% of zeolite, Treatment C with 5% of biochar, and Treatment D with 5% of zeolite and 5% biochar, respectively. The AOB and AOA amoA gene abundance as well as the ammonia monooxygenase (AMO) activity were estimated by quantitative PCR and enzyme-linked immunosorbent assay, respectively. The relationship between gene abundance and AMO enzyme activity was determined by regression analysis. Results indicated that the AOB was more abundant than that of AOA throughout the composting process. Addition of biochar and its integrated application with zeolite promoted the AOB community abundance and AMO enzyme activity. Significant positive relationships were obtained between AMO enzyme activity and AOB community abundance (r2 = 0.792; P < 0.01) and AOA community abundance (r2 = 0.772; P < 0.01), indicating that both bacteria and archaea played significant roles in microbial ammonia oxidation during composting. Using biochar and zeolite might promote the nitrification activity by altering the sample properties during agricultural waste composting.