Abstract：
Numerous efforts have been made to enhance the performance of anaerobic digestion (AD) for accelerating renewable energy generation, however, it remains unclear whether the intensified measures could enhance the proliferation and transmissions of antibiotic resistance genes (ARGs) in the system. This study assessed the impact of an innovative pig manure AD process, which includes hydrothermal pretreatment (HTP) and a two-stage configuration with separated acidogenic and methanogenic phases, on biomethane (CH4) production and ARGs dynamics. Results showed that HTP significantly increase CH4 production from 0.65 to 0.75 L/L/d in conventional single-stage AD to 0.82 and 0.91 L/L/d in two-stage AD. This improvement correlated with a rise in the relative abundance of Methanosarcina, a key methanogenesis microorganism. In the two-stage AD, the methanogenic stage offered an ideal environment for methanogens growth, resulting in substantially faster and higher CH4 production by about 10% compared to single-stage AD. Overall, the combined use of HTP and the two-stage AD configuration enhanced CH4 production by 40% compared to traditional single-stage AD. The abundance and diversity of ARGs were significantly reduced in the acidogenic reactors after HTP. However, the ARGs levels increased by about two times in the following methanogenesis stage and reached similar or higher levels than in single stage AD. The erm(F), erm(G), ant(6)-Ia, tet(W), mef(A) and erm(B) were the six main ARGs with significant differences in relative abundances in various treatments. The two-stage AD mode could better remove sul2, but it also had a rebound which elevated the risk of ARGs to the environment and human health. Network analysis identified pH and TVFAs as critical factors driving microbial communities and ARG proliferation in the new AD process. With the results, this study offers valuable insights into the trade-offs between AD performance enhancement and ARG-related risks, pinpointing essential areas for future research and practical improvements.
摘要：
已经做出了许多努力来提高厌氧消化（AD）的性能，以加速可再生能源的产生，然而,目前尚不清楚强化措施是否能增强抗生素抗性基因(ARGs)在系统中的增殖和传播.这项研究评估了创新的猪粪AD过程的影响，其中包括水热预处理（HTP）和具有分离的产酸和产甲烷阶段的两阶段配置，生物甲烷(CH4)生产和ARGs动态。结果表明，HTP可将常规单级AD中的CH4产量从0.65至0.75L/L/d显着提高到两级AD中的0.82和0.91L/L/d。这种改善与甲烷的相对丰度增加有关，一种关键的产甲烷微生物。在两阶段广告中，产甲烷阶段为产甲烷菌的生长提供了理想的环境，导致显著更快和更高的CH4生产约10％相比，单级AD。总的来说,与传统的单级AD相比，HTP和两级AD配置的结合使用使CH4的产量提高了40％。在HTP后的产酸反应器中，ARGs的丰度和多样性显着降低。然而,在随后的产甲烷阶段，ARGs水平增加了约两倍，并且达到了与单阶段AD相似或更高的水平。erm(F)，erm(G),ant(6)-Ia，tet(W),mef（A）和erm（B）是六种主要的ARG，在各种处理中相对丰度存在显着差异。两阶段AD模式可以更好地去除sul2，但也有反弹，这增加了ARGs对环境和人类健康的风险。网络分析确定pH和TVFAs是新AD过程中驱动微生物群落和ARG增殖的关键因素。有了结果,这项研究为AD性能增强和ARG相关风险之间的权衡提供了有价值的见解，确定未来研究和实际改进的重要领域。
