摘要

       铜是猪粪中含量最丰富的重金属之一。在这项研究中，实验室规模的好氧堆肥系统在三个水平（0、200 和 2000 mg kg-1，即对照、Cu200 和 Cu2000 处理）中使用 Cu 进行修正，以确定其对铜抗性基因 [铜抗性基因 (CRG)：pcoA、cusA、copA 和 tcrB]、抗生素抗性基因 [抗生素抗性基因 (ARG)：erm(A) 和 erm(B)] 和 intl1。结果表明，猪粪堆肥后pcoA、tcrB、erm(A)、erm(B)和intl1的绝对丰度降低，而copA和cusA的绝对丰度增加。冗余分析表明，温度显着影响 CRGs、ARGs 和 intl1 的变化。 CRGs、ARGs 和 intI1 的减少与可交换的 Cu 水平呈正相关。细菌群落可以根据不同处理下的堆肥时间进行分组，其中高浓度的铜对细菌群落的影响更持久。网络分析确定 CRGs、ARGs 和 intI1 的共存以及细菌群落是 CRGs、ARG 和 intl1 变化的主要贡献者。因此，温度、铜和细菌群落组成的变化对添加铜的粪便堆肥过程中 CRG、ARG 和 intl1 的变化具有重要影响。

       Copper is one of the most abundant heavy metals present in swine manure. In this study, a laboratory-scale aerobic composting system was amended with Cu at three levels (0, 200, and 2000 mg kg-1, i.e., control, Cu200, and Cu2000 treatments, respectively) to determine its effect on the fate of copper resistance genes [copper resistance genes (CRGs): pcoA, cusA, copA, and tcrB], antibiotic resistance genes [antibiotic resistance genes (ARGs): erm(A) and erm(B)], and intl1. The results showed that the absolute abundances of pcoA, tcrB, erm(A), erm(B), and intl1 were reduced, whereas those of copA and cusA increased after swine manure composting. Redundancy analysis showed that temperature significantly affected the variations in CRGs, ARGs, and intl1. The decreases in CRGs, ARGs, and intI1 were positively correlated with the exchangeable Cu levels. The bacterial community could be grouped according to the composting time under different treatments, where the high concentration of copper had a more persistent effect on the bacterial community. Network analysis determined that the co-occurrence of CRGs, ARGs, and intI1, and the bacterial community were the main contributors to the changes in CRGs, ARG, and intl1. Thus, temperature, copper, and changes in the bacterial community composition had important effects on the variations in CRGs, ARGs, and intl1 during manure composting in the presence of added copper.

https://www.frontiersin.org/articles/10.3389/fmicb.2017.00344/full