摘要
      好氧堆肥通常用于猪粪处理，然而，抗生素抗性基因（ARGs）及其在堆肥过程中的不明确转化使处理后的粪肥土地使用具有风险。研究了猪粪堆肥过程中强化嗜热阶段策略（外部加热（HTC）和嗜热菌接种（MC））对ARGs去除的影响及其潜在机制。在堆肥结束时，与对照相比，HTC使ARGs的总相对丰度（RA）增加了32.38%，MC减少了21.50%。Mantel试验表明，不是温度（P>0.05），而是环境参数（pH、电导率（EC）等）和代谢产物（氮形式）显著影响ARGs的分布。偏最小二乘路径模型（PLS-PM）表明，微生物群落结构（细菌丰度和多样性）是ARGs进化的主要因素。共现分析表明，HTC可以促进ARG宿主在堆肥后期的繁殖，因为嗜热菌的强烈选择导致生态位空缺，而MC通过增加嗜热菌多样性来增强宿主和非宿主之间对生态位的竞争。这些结果表明，对潜在ARGs宿主的竞争抑制可能是堆肥过程中消除ARGs威胁的一种有用策略。

Abstract
Aerobic composting is commonly used in pig manure treatment, however, antibiotic resistance genes (ARGs) and their unclear transformation during composting process make the treated manure land using risky. The effects of enhanced thermophilic phase strategy (external heating (HTC) and thermophiles inoculation (MC)) on ARGs removal and the underlying mechanisms were investigated during swine manure composting. HTC increased the total relative abundance (RA) of ARGs by 32.38%, and MC decreased by 21.50% compared to CK by the end of the composting. Mantel test indicated that it was not temperature (P > 0.05), but environmental parameters (pH, Electric Conductivity (EC), etc.) and metabolic products (nitrogen forms) significantly affected the ARGs profile. Partial least-squares path modeling (PLS-PM) suggested that microbial community structure (bacterial abundance and diversities) was the main factor for ARGs evolution. Co-occurrence analysis revealed that HTC could promote the propagation of ARG hosts in later stage of the composting because the strong selection of thermophiles resulted in ecological niches vacancy, and MC enhanced the competition between hosts and nonhosts for ecological niches by increasing thermophiles diversities. These results suggested that competitive inhibition to potential ARGs hosts could be a helpful strategy in ARGs threaten elimination during composting.

https://www.sciencedirect.com/science/article/abs/pii/S0304389421021178