摘要

    堆肥和厌氧消化技术被广泛用于粪便回收，但是这些方法在去除抗生素，抗生素抗性基因（ARG）和重金属方面显示出相互矛盾的结果。在本研究中，以工业规模研究了厌氧消化的鸡粪和各种堆肥鸡粪。抗生素，ARG和重金属在厌氧消化和堆肥方面显示出不一致的结果。不同的堆肥过程降低或完全去除了blaCTX-M，intl1和oqxB基因。此外，堆肥过程降低了aac6’-Ib和aadA基因的绝对丰度，而增加了qnrD，sul1和tet（A）基因的绝对丰度。另一方面，鸡粪的厌氧消化增加了ere（A）和tet（A）的绝对丰度。高通量测序结果表明，杂菌，变形杆菌，拟杆菌和放线菌在堆肥和厌氧消化样品的总细菌组成中占主导地位。网络分析显示ARG和intl1同时存在。冗余分析显示某些重金属和ARG之间存在显着相关性。同样，细菌组成与处理过的粪便中ARG的发生率呈正相关。这些发现表明，在堆肥和厌氧消化过程中，细菌群落，重金属和可移动的遗传元素可在ARG的丰富和变异中发挥重要作用。总之，为了有效地去除鸡粪中的抗生素，ARG和重金属，需要改进工业规模的厌氧消化和堆肥方法。

    Composting and anaerobic digestion techniques are widely used for manure recycling, but these methods have shown conflicting results in the removal of antibiotics, antibiotic resistance genes (ARGs), and heavy metals. In the present study, anaerobically digested chicken manure and various types of composted chicken manure were investigated on an industrial scale. Antibiotics, ARGs, and heavy metals had shown inconsistent results for anaerobic digestion and composting. The different composting processes either declined or completely removed the blaCTX-M, intl1 and oqxB genes. In addition, composting processes decreased the absolute abundance of aac6’-Ib and aadA genes, while increased the absolute abundance of qnrD, sul1, and tet(A) genes. On the other hand, anaerobic digestion of chicken manure increased the absolute abundance of ere(A) and tet(A). High throughput sequencing showed that Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria dominated the total bacterial composition of composted and anaerobically digested samples. Network analysis revealed the co-occurrence of ARGs and intl1. The redundancy analysis showed a significant correlation between some heavy metals and ARGs. Similarly, the bacterial composition showed a positive correlation with the prevalence of ARGs in treated manure. These findings suggest that bacterial community, heavy metals, and mobile genetic elements can play a significant role in the abundance and variation of ARGs during composting and anaerobic digestion. In conclusion, anaerobic digestion and composting methods at industrial scale need to be improved for the effective removal of antibiotics, ARGs and heavy metals from chicken manure.

    https://www.sciencedirect.com/science/article/abs/pii/S0048969720309244