State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, China.
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, China.
J Hazard Mater. 2022 Sep 15;438:129535. doi: 10.1016/j.jhazmat.2022.129535. Epub 2022 Jul 5.
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 × 10 gene copies/g dry total solids (TS), ~1 log lower than that in the AD without pretreatment (3.55 ×10 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.
猪粪是抗生素抗性的重要储存库。厌氧消化（AD）是一种常用于处理猪粪的常见生物过程，但在沼气生产和抗生素抗性去除方面仍面临效率低下的问题。本研究表明，添加游离亚硝酸预处理（FNA）的 AD 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=250mgN/L，pH=5.0，温度=20±1°C）可同时减少抗生素（四环素类、醌类和磺胺类），使抗生素抗性菌（ARB）失活 0.5-3 个对数级，并分别使 tet、sul 和 qnr 基因减少 1-2、1-3 和 0.5 个对数级。在随后的 AD 步骤中，总残留 ARGs 减少到约 3.49×10 基因拷贝/g 干总固体（TS），比未经预处理的 AD 低约 1 个对数级（3.55×10 基因拷贝/g 干 TS）。微生物群落和网络分析表明，ARGs 的去除主要是由于 FNA 直接作用于减少 ARGs 和抗生素，而与 ARB 无关。此外，FNA 预处理使猪粪的生物化学甲烷生产潜力增加了一倍。这些结果表明，添加游离亚硝酸预处理的 AD 是一种非常有用的工艺，可极大地促进猪粪管理。
