Changes in microbial community structure during pig manure composting and its relationship to the fates of antibiotics and antibiotic resistance genes

Publication date: Available online 23 January 2020Source: Journal of Hazardous MaterialsAuthor(s): Yuanwang Liu, Dengmiao Cheng, Jianming Xue, Louise Weaver, Steve A. Wakelin, Yao Feng, Zhaojun LiAbstractAnimal manure containing veterinary antibiotics is a significant source of microbial antibiotic resistance genes (ARGs). Composting of animal manure with wheat straw and sawdust was explored as a means to reduce ARGs load in the final material. The effects of ciprofloxacin, oxytetracycline, sulfamerazine on the bacterial community composition, and how this then affected the removal of seven tetracycline resistance genes (TARGs), four sulfonamide resistance genes (SARGs), and two fluoroquinolone resistance genes (QARGs) were investigated. Treatments receiving either ciprofloxacin or the three mixed antibiotics had reduced bacterial alpha-diversity and displayed shifts in the abundance of Proteobacteria and Firmicutes. This demonstrated that different antibiotics played an important role in bacterial community composition. Furthermore, variation in the physicochemical properties of compost, particularly pH and temperature, was also strongly linked to shifts in bacterial composition over time. Based on network analysis, the reduction of TARGs were associated with loss of Pseudomonas, Pseudoxanthomonas, Pusillimonas, Aquamicrobium, Ureibacillus, Lysinibacillus, Bacillus and Brachybacterium during the thermophilic stage. However, QARGs and SARGs were more strongly affected by the ...
Source: Journal of Hazardous Materials - Category: Environmental Health Source Type: research