Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China; College of Environment, Hohai University, Nanjing, 210098, China.
Institute of Water Science and Technology, Hohai University, Nanjing, 210098, China; The National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210098, China.
J Environ Manage. 2024 Jun;360:121090. doi: 10.1016/j.jenvman.2024.121090. Epub 2024 May 20.
Microplastics (MPs) and antibiotic resistance genes (ARGs) are important pollutants in waste activated sludge (WAS), but their interactions during anaerobic digestion (AD) still need to be further explored. This study investigated variations in ARGs, mobile genetic elements (MGEs), and host bacteria during AD under the pressure of polyamide (PA), polyethylene (PE), and polypropylene (PP). The results showed that the MPs increased methane production by 11.7-35.5%, and decreased ARG abundance by 5.6-24.6%. Correlation analysis showed that the decrease of MGEs (plasmid, prophage, etc.) promoted the decrease of the abundance of multidrug, aminoglycoside and tetracycline resistance genes. Metagenomic annotation revealed that the reduction of key host bacteria (Arenimonas, Lautropia, etc.) reduced the abundance of major ARGs (rsmA, rpoB2, etc.). Moreover, PP MPs contributed to a reduction in the abundance of functional genes related to the production of reactive oxygen species, ATP synthesis, and cell membrane permeability, which was conducive to reducing the potential for horizontal gene transfer of ARGs. These findings provide insights into the treatment of organic waste containing MPs.
微塑料 (MPs) 和抗生素耐药基因 (ARGs) 是废活性污泥 (WAS) 中的重要污染物，但它们在厌氧消化 (AD) 过程中的相互作用仍需进一步探索。本研究在聚酰胺 (PA)、聚乙烯 (PE) 和聚丙烯 (PP) 的压力下，研究了 AD 过程中 ARGs、移动遗传元件 (MGEs) 和宿主细菌的变化。结果表明， MPs 使甲烷产量增加了 11.7-35.5%，并使 ARG 丰度降低了 5.6-24.6%。相关性分析表明，MGEs（质粒、噬菌体等）的减少促进了多药、氨基糖苷类和四环素耐药基因丰度的降低。宏基因组注释表明，关键宿主细菌（Arenimonas、Lautropia 等）的减少降低了主要 ARGs（rsmA、rpoB2 等）的丰度。此外，PP MPs 有助于减少与活性氧产生、ATP 合成和细胞膜通透性相关的功能基因的丰度，这有利于降低 ARGs 水平基因转移的潜力。这些发现为含有 MPs 的有机废物的处理提供了新的思路。
