摘要
      猪粪是抗生素耐药性的重要来源。厌氧消化（AD）是一种用于处理猪粪的常见生物过程，但在沼气生产和抗生素耐药性去除方面仍然面临低效率。研究表明，AD与游离亚硝酸预处理（FNA）可有效降低猪粪中的抗生素抗性基因（ARGs）。FNA预处理（亚硝酸盐=250 mg N/L，pH=5.0，温度=20±1°C）同时减少抗生素（四环素类、醌类和磺酰胺类），使抗生素耐药性细菌（ARB）失活0.5–3个对数，并使ARGs tet、sul和qnr分别减少1–2、1–3和0.5个对数。在接下来的AD步骤中，总残留ARGs减少到约3.49×107个基因拷贝/g干总固体（TS），比未经预处理的AD（3.55×108个基因拷贝g/g干TS）低约1个对数。微生物群落和网络分析表明，ARG的去除主要是由FNA对减少ARG和抗生素的直接作用驱动的，与ARB无关。此外，FNA预处理使猪粪产生生化甲烷的潜力增加了一倍。总之，这些结果表明，AD和FNA预处理是一种有用的过程，极大地促进了猪粪管理。
Abstract
Swine manure is a significant reservoir for antibiotic resistance. Anaerobic digestion (AD) is a common biological process used to treat swine manure but still faces low efficiencies in biogas production and antibiotic resistance removal. It is here shown that AD with free nitrous acid pretreatment (FNA) was effective in reducing antibiotic resistance genes (ARGs) in swine manure. FNA pretreatment (nitrite =250 mg N/L, pH=5.0, temperature=20 ± 1 °C) simultaneously reduced antibiotics (Tetracyclines, Quinones and Sulfonamides), inactivated antibiotics resistance bacteria (ARB) by 0.5–3 logs, and decreased ARGs tet, sul and qnr by 1–2, 1–3 and 0.5 logs, respectively. In the following AD step, the total residual ARGs was reduced to ~3.49 × 107 gene copies/g dry total solids (TS), ~1 log lower than that in the AD without pretreatment (3.55 ×108 gene copies/g dry TS). Microbial community and network analyses revealed that the ARG removal was mainly driven by the direct FNA effect on reducing ARGs and antibiotics, not related to ARB. Besides, the FNA pretreatment doubled biochemical methane production potential from swine manure. Together these results demonstrate that AD with FNA pretreatment is a useful process greatly facilitating swine manure management.

https://www.sciencedirect.com/science/article/abs/pii/S0304389422013280