We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Impacts of microplastic type on the fate of antibiotic resistance genes and horizontal gene transfer mechanism during anaerobic digestion
Summary
Researchers examined how three types of microplastics affect antibiotic resistance genes during the anaerobic digestion of sewage sludge. They found that while microplastics actually increased methane production, they also decreased the overall abundance of antibiotic resistance genes but changed how those genes spread between bacteria. The study reveals a complex interaction where microplastics may reduce some resistance genes while promoting the horizontal transfer of others during waste treatment.
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.