摘要
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厌氧消化（AD）已被广泛用于将各种生物废物转化为可再生能源。然而，庆大霉素菌丝体残留物（GMRs，庆大霉素生产的副产品）的AD受到氨抑制和抗微生物耐药性风险的限制。与GMRs的中温AD（MMAD）相比，本研究考察了三个半连续的AD过程，即与麦草共消化、高温消化（TAcoD）和缩短停留时间（RT）的AD。结果表明，在合适的操作条件下，可以实现稳定、安全的AD。共消化可以有效地减轻氨抑制的不利影响。与MMAD相比，TAcoD的甲烷产量增加了35.86%，危险废物减少了43.99%。关于AD系统的耐药性，庆大霉素被有效降解，并且降解过程不参与与修饰酶相关的抗生素耐药性基因（ARGs）的表达。在三种操作策略下有效去除ARGs与潜在宿主的细菌丰度的更高降低有关。此外，PICRUSt预测的转化和结合相关蛋白的变化表明，嗜热条件和较短的RT有助于降低ARGs的传播风险。
Abstract
Abstract Image
Anaerobic digestion (AD) has been widely employed for converting various biowastes into renewable energy. However, AD of gentamicin mycelial residues (GMRs, a byproduct of gentamicin production) is limited by ammonia inhibition and antimicrobial resistance risk. Compared to mesophilic AD (MMAD) of GMRs, this study looked into three semicontinuous AD processes, i.e., codigestion with wheat straw, thermophilic digestion (TAcoD), and AD at shortened retention time (RT). Results showed that a stable and safe AD could be achieved under suitable operating conditions. Co-digestion could effectively mitigate the adverse effect of ammonia inhibition. The methane production increased by 35.86% in TAcoD compared to that in MMAD and 43.99% of hazardous waste was reduced in TAcoD. Concerning the antimicrobial resistance of AD system, gentamicin was degraded efficiently and the degradation process was not involved in the expression of antibiotic resistance genes (ARGs) related to modifying enzyme. Effective removal of ARGs under three operating strategies was associated with a higher reduction in bacterial abundance of potential hosts. In addition, the changes in the relevant proteins for transformation and conjugation as predicted by PICRUSt suggested that thermophilic condition and shorter RT were conducive to the reduction of the dissemination risks of ARGs.

https://pubs.acs.org/doi/abs/10.1021/acs.est.2c00481