摘要
      污泥的热水解是缓解厌氧消化（AD）中抗生素抗性基因（ARGs）传播的一种很有前途的方法。尽管污泥中的ARGs可能会分解为细胞内、细胞外聚合物（EPS）相关和无细胞的ARG，但这些不同部分在AD中的命运从未被研究过。本研究详细描述了在90°C和140°C下热水解污泥AD中细胞内和细胞外ARGs的特征。EPS相关的ARGs代表了所有样品中总细胞外ARGs的主要部分，而在140°C的热水解中观察到其最低丰度以及最低的EPS水平。结果表明，EPS相关的ARGs与细胞内和无细胞ARGs呈正相关。此外，各种EPS成分，如蛋白质和e-DNA，与β-内酰胺抗性基因呈正相关。sul1作为EPS相关的抗性基因在所有样品中占主导地位。这些结果为不同ARGs组分在与热水解结合的AD中的总体传播的意义提供了新的见解。
Abstract
Thermal hydrolysis of sludge is a promising approach to mitigate antibiotic resistance genes (ARGs) propagation in anaerobic digestion (AD). Although ARGs in sludge may be fractioned into intracellular, extracellular polymeric substance (EPS)-associated, and cell-free ARGs, the fate of these different fractions in AD has never been investigated. This study presents a detailed characterization of intracellular and extracellular ARGs in AD of sludge thermally hydrolyzed at 90 °C and 140 °C. EPS-associated ARGs represented the major fraction of the total extracellular ARGs in all samples, while its lowest abundance was observed for thermal hydrolysis at 140 °C along with the lowest EPS levels. The results suggested a positive correlation between EPS-associated ARGs with intracellular and cell-free ARGs. Furthermore, various EPS components, such as proteins and e-DNA, were positively correlated with β-lactam resistance genes. sul1 dominated all samples as an EPS-associated resistance gene. These results provide new insights into the significance of different ARGs fractions in their overall dissemination in AD integrated with thermal hydrolysis.

https://www.sciencedirect.com/science/article/abs/pii/S0048969722059460