Zero valent iron improved methane production and specifically reduced aminoglycoside and tetracycline resistance genes in anaerobic digestion. (December 2021)

• Record Type: Journal Article
• Authors: Zhang, Junya; Lu, Tiedong; Zhong, Hui; Shen, Peihong; Wei, Yuansong
• Is Part Of: Waste management. Volume 136(2021)
• Page Start: 122
• Page End: 131
• Publication Date: 2021-12
• Subjects: Zero valent iron -- Anaerobic digestion -- Antibiotic resistance genes -- High-throughput qPCR -- Swine manure; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2021.10.010
• Languages: English
• ISSNs: 0956-053X

Abstract

Graphical abstract: Highlights: ZVI improved methane production and ARGs reduction by 23.9% and 25.0%, respectively. Methane production was improved through chemical reaction and DIET induced by ZVI. Microbial community evolution explained the fate of most of ARGs. ZVI reduced tetracycline resistance genes probably by ionic balance disturbance. Aminoglycoside resistance genes were reduced related to enzyme activity inhibition. Abstract: It is unadvisable to discuss the antibiotic resistance genes (ARGs) reduction in anaerobic digestion (AD) system neglecting its main purpose-methane production. The methane production improvement coupling with antibiotic resistance genes (ARGs) reduction in anaerobic digestion (AD) by zero valent iron (ZVI) were simultaneously investigated. Whether the role of ZVI on the ARGs fate was random or specific was clarified through the high-throughput qPCR (HT-qPCR). Results indicated that ZVI improved methane production and ARGs reduction by 23.9% and 25.0%, respectively. The improved methane production was associated with chemical reaction and variances of microbial community caused by ZVI, where DIET between Petrimonas, Clostridium and Syntrophomonas, Methanosarcina was established along with ACAS being enriched. ZVI specifically, not randomly, facilitated the reduction of aminoglycoside resistance genes of antibiotic inactivation and tetracycline resistance genes of ribosomal protection proteins. The specifical reduction could be attributed to enzyme activity inhibition and intracellular ionic disturbance caused by higher amounts of ZVI, although most of ARGs fate could be well explained by microbial community which contributed the most to ARGs dynamics as a whole. ZVI-based AD was a promising way for the improvement of methane production coupling ARGs reduction.