Chen Zhiqiang, Fu Qiqi, Wen Qinxue, Wu Yiqi, Bao Huanyu, Guo Jingbo
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin 150090, PR China.
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin 150090, PR China.
J Hazard Mater. 2022 Feb 5;423(Pt B):127149. doi: 10.1016/j.jhazmat.2021.127149. Epub 2021 Sep 9.
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.
好氧堆肥常用于猪粪处理，然而，抗生素抗性基因（ARGs）及其在堆肥过程中不明确的转化使得处理后的粪肥土地利用存在风险。在猪粪堆肥过程中，研究了强化嗜热阶段策略（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。堆肥结束时，HTC使ARGs的总相对丰度（RA）增加了32.38%，而MC与对照相比降低了21.50%。Mantel检验表明，显著影响ARGs分布的不是温度（P>0.05），而是环境参数（pH值、电导率（EC）等）和代谢产物（氮形态）。偏最小二乘路径建模（PLS-PM）表明，微生物群落结构（细菌丰度和多样性）是ARGs演变的主要因素。共现分析表明，HTC可在堆肥后期促进ARGs宿主的繁殖，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增强了宿主与非宿主之间对生态位的竞争。这些结果表明，对潜在ARGs宿主的竞争性抑制可能是堆肥过程中消除ARGs威胁的一种有效策略。
