摘要

使用宏基因组学和定量PCR（qPCR）在厌氧消化（AD）中评估了对氨胁迫的抗生素抗性基因（ARG）响应的动力学。由于游离氨（FA）改变了外排系统的质子梯度，氨胁迫降低了与抗生素外排相关的ARG，尤其是tet（L）的主要促进子超家族（MFS）。尽管如此，在氨气胁迫下，抗生素靶标改变的ARGs（尤其是ermB）富集了，这可能归因于广泛宿主质粒pAMbeta1转移性内部增强子的启动。统计分析表明ARGs的显着变化直接归因于移动遗传元件（MGEs），但受影响较小的ARGs主要由氮循环基因（NCyc）反映的功能性微生物决定。这项研究破译了ARGs对AD中氨胁迫的反应，表明缓解氨抑制作用对于缓解ARGs的传播很重要。

The dynamics of antibiotic resistance genes (ARGs) response to ammonia stress were evaluated using metagenomics and quantitative PCR (qPCR) in anaerobic digestion (AD). Ammonia stress reduced ARGs associated with antibiotic efflux, especially the major facilitator superfamily (MFS) of tet(L), due to free ammonia (FA) that changed the proton gradient of efflux system. Nonetheless, ARGs of antibiotic target alteration, especially ermB, were enriched under ammonia stress, which could be attributed to the initiation of the internal enhancer of the transferability of the broad host range plasmid, pAMbeta1. Statistical analysis elucidated the significant changes of ARGs are directly attributed to the mobile genetic elements (MGEs), but the little affected ARGs are mainly determined by the functional microbes reflected by nitrogen cycling genes (NCyc). This study deciphered the profiles of ARGs response to ammonia stress in AD, which indicated the importance of alleviation of ammonia inhibition for the mitigation of ARGs dissemination.

https://www.ncbi.nlm.nih.gov/pubmed/31634801