Impacts of addition of natural zeolite or a nitrification inhibitor on antibiotic resistance genes during sludge composting. (15th March 2016)

• Record Type: Journal Article
• Authors: Zhang, Junya; Chen, Meixue; Sui, Qianwen; Tong, Juan; Jiang, Chao; Lu, Xueting; Zhang, Yuxiu; Wei, Yuansong
• Is Part Of: Water research. Volume 91(2016)
• Page Start: 339
• Page End: 349
• Publication Date: 2016-03-15
• Subjects: Antibiotic resistance genes -- Sludge composting -- Natural zeolite -- 3, 4-Dimethylpyrazole phosphate (DMPP) -- Bacterial community; ARGs antibiotic resistance genes -- ARB antibiotic resistance bacteria -- DMPP 3, 4-Dimethylpyrazole phosphate -- MGEs mobile genetic elements -- HGT Horizontal gene transfer -- WWTPs Wastewater treatment plants -- MRGs Heavy metal resistance genes -- qPCR Quantitative PCR -- DW Dry weight; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2016.01.010
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: Composting is commonly used for the treatment and resource utilization of sewage sludge, and natural zeolite and nitrification inhibitors can be used for nitrogen conservation during sludge composting, while their impacts on ARGs control are still unclear. Therefore, three lab-scale composting reactors, A (the control), B (natural zeolite addition) and C (nitrification inhibitor addition of 3, 4-dimethylpyrazole phosphate, DMPP), were established. The impacts of natural zeolite and DMPP on the levels of ARGs were investigated, as were the roles that heavy metals, mobile genetic elements (MGEs) and the bacterial community play in ARGs evolution. The results showed that total ARGs copies were enriched 2.04 and 1.95 times in reactors A and C, respectively, but were reduced by 1.5% in reactor B due to the reduction of conjugation and co-selection of heavy metals caused by natural zeolite. Although some ARGs ( bla CTX-M, bla TEM, ermB, ereA and tetW ) were reduced by 0.3–2 logs, others ( ermF, sulI, sulII, tetG, tetX, mefA and aac(6′)-Ib-cr ) increased by 0.3–1.3 logs after sludge composting. Although the contributors for the ARGs profiles in different stages were quite different, the results of a partial redundancy analysis, Mantel test and Procrustes analysis showed that the bacterial community was the main contributor to the changes in ARGs compared to MGEs and heavy metals. Network analysis determined the potential host bacteria for various ARGs and further confirmed our results. Graphical abstract: Highlights: Natural zeolite addition was effective for ARGs control during sludge composting. Relationship of ARGs and MGEs, MRGs and bacterial community was investigated. MGEs contribute most to the ARGs profiles at thermophilic and cooling stage. Addition of natural zeolite and DMPP had little impact on bacterial community. Bacterial community was the main contributor to the evolution of ARGs.