摘要
      牲畜粪便中存在大量抗生素抗性基因（ARGs），这对生态系统构成了迫在眉睫的严峻安全风险。为了更全面地研究基于生物炭添加的畜禽粪便工业规模堆肥中ARGs的去除机制，我们跟踪了10%生物炭畜禽粪便好氧堆肥不同阶段的细菌群落和ARGs动态。生物炭对细菌群落和ARGs的分布没有显著影响。在好氧堆肥过程中，ARGs和可移动遗传元素（MGEs）的相对丰度总体上呈先下降后上升的趋势。驱动ARGs动力学的关键因素是细菌群落组成，ARGs的潜在宿主是Caldicoprobericter、Tepidimicrobium、Ignatzschineria、Pseudogracillibacillus、Actinomadura、Flavobacterium和Planifilum。嗜热细菌的保留和初始细菌的重新繁殖是成熟阶段ARGs增加的主要原因。此外，在MGE中，转座子基因的相对丰度基本上被去除，而整合素基因保持在较高的相对丰度。我们的研究结果强调，生物炭添加到工业规模好氧堆肥中的适用性需要进一步探索，并且需要采取有效措施来防止ARGs含量在成熟阶段增加。
Abstract
The presence of large amounts of antibiotic resistance genes (ARGs) in livestock manures poses an impending, tough safety risk to ecosystems. To investigate more comprehensively the mechanisms of ARGs removal from industrial-scale composting of livestock manure based on biochar addition, we tracked the dynamics of bacterial community and ARGs at various stages of aerobic composting of livestock manures with 10% biochar. There were no significant effects of biochar on the bacterial community and the profiles of ARGs. During aerobic composting, the relative abundance of ARGs and mobile genetic elements (MGEs) showed overall trends of decreasing and then increasing. The key factor driving the dynamics of ARGs was bacterial community composition, and the potential hosts of ARGs were Caldicoprobacter, Tepidimicrobium, Ignatzschineria, Pseudogracilibacillus, Actinomadura, Flavobacterium and Planifilum. The retention of the thermophilic bacteria and the repopulation of the initial bacteria were the dominant reasons for the increase in ARGs at maturation stage. Additionally, among the MGEs, the relative abundance of transposon gene was substantially removed, while the integron genes remained at high relative abundance. Our results highlighted that the suitability of biochar addition to industrial-scale aerobic composting needs to be further explored and that effective measures are needed to prevent the increase of ARGs content on maturation stage.

https://www.sciencedirect.com/science/article/abs/pii/S0269749122014841