摘要

       抗生素抗性基因 (ARG) 在食物垃圾 (FW) 处理过程中的传播会对公众健康构成严重威胁。脂质是 FW 的主要成分，而脂质应激是否会影响 FW 厌氧消化 (AD) 过程中的 ARGs 动力学尚不确定。本研究的重点是脂肪胁迫对甲烷产生、ARGs 的归宿及其在 FW 的 AD 过程中的微生物机制的影响。结果表明，与无油 FW 的 AD 相比，高脂质含量增加了甲烷产量，但延长了水解和甲烷产生的滞后时间。此外，ARG 的变异更容易受到脂质应激的影响。与无油组相比，脂质应激可促进总 ARGs 丰度的降低，特别是抑制 AD 系统中 sul1、aadA1 和 mefA 的增殖（P < 0.05）。 Mantel 检验表明整合子（intl1 和 intl2）与所有检测到的 ARG 显着相关（r：0.33，P < 0.05），表明由整合子介导的水平基因转移可能是 ARG 传播的驱动力。网络分析表明，厚壁菌门、拟杆菌门、协同菌门和变形菌门是 ARG 的主要潜在宿主。此外，在脂质压力下，宿主细菌的减少负责消除几种特定的 ARG，从而影响 ARG 谱。这些发现首先破译了 ARGs 动力学及其在 FW 厌氧生物处理过程中响应脂质应激的驱动因素。

       The dissemination of antibiotic resistance genes (ARGs) in food waste (FW) disposal can pose severe threats to public health. Lipid is a primary composition in FW, while whether lipid stress can affect ARGs dynamics during anaerobic digestion (AD) process of FW is uncertain. This study focused on the impacts of lipid stress on methane production, fate of ARGs and its microbial mechanisms during AD of FW. Results showed that high lipid content increased methane yield but prolonged hydrolysis and lag time of methane production compared to AD of FW without oil. Moreover, variations of ARGs were more susceptible to lipid stress. Lipid stress could facilitate the reduction of total ARGs abundances compared to the group without oil, particularly restraining the proliferation of sul1, aadA1 and mefA in AD systems (P < 0.05). Mantel test suggested that integrons (intl1 and intl2) were significantly correlated with all detected ARGs (r: 0.33, P < 0.05), indicating that horizontal gene transfer mediated by integrons could be the driving force on ARGs dissemination. Network analysis suggested that Firmicutes, Bacteroidetes, Synergistetes and Proteobacteria were the main potential hosts of ARGs. In addition, under the lipid stress, the reduction of host bacteria was responsible for the elimination of several specific ARGs, thereby affecting ARGs profiles. These findings firstly deciphered ARGs dynamics and their driving factors responding to lipid stress during anaerobic biological treatment of FW.

https://www.sciencedirect.com/science/article/abs/pii/S0048969720373770