Anaerobic sulfamethoxazole‐degrading bacterial consortia in antibiotic‐contaminated wetland sediments identified by DNA‐stable isotope probing and metagenomics analysis

Abstract

Summary Anaerobic degradation has been demonstrated as an important pathway for the removal of sulfonamide (SA) in contaminated environments, and identifying the microorganisms responsible for the degradation of SA is a key step in developing bioaugmentation approaches. In this study, we investigated the anaerobic degradation activity of three SA [sulfadiazine (SDZ), sulfamethazine (SMZ) and sulfamethoxazole (SMX)] and the associated bacterial community in wetland sediments contaminated by aquaculture (in Fujian Province, coded with FJ), livestock farming (in Sichuan Province, coded with SC), or rural wastewaters (in Guangdong Province, coded with GD). Additionally, the combination of DNA‐stable isotope probing (SIP) with metagenomics was further applied to assess the active SA‐degrading microbes using SMX as a model SA. Among SDZ, SMZ and SMX, only SMX could be effectively dissipated, and the degradation of SMX was relatively fast in the microcosms of sediments with higher levels of SA contamination (FJ and SC). The anaerobic biotransformation pathway of SMX was initiated by hydrogenation with the cleavage of the N–O bond on the isoxazole ring. DNA‐SIP revealed that the in situ active anaerobic SMX‐degraders (5, 18 and 3 genera in sediments FJ, SC and GD respectively) were dominated by Proteobacteria in sediments FJ and SC, but by Firmicutes (two Family XVIII members) in sediment GD. Mycobacterium, unclassified Burkholderiaceae and Rhodocyclaceae were identified as the dominant active SMX‐degrading bacteria in both sediments FJ and SC. Higher proportions of antibiotic resistance gene and genes involved in various functional categories were observed in sediments FJ and SC.

Occurrence and Composition Patterns of ARGs in Plant-Microbial Synergism Were Negatively Reconstructed by an Electrochemical Technology at Low Temperatures

“…Burkholderiaceae, as an important multidrug-resistant bacterium with an RA of 14.6% in L-E-Fe, was bound up with environmental saprophytes, conditional pathogens, and major pathogens of humans, plants, and animals Mycobacterium was one of the major known SMX-degrading bacteria, which was only found in L-E-Fe. The MAG (D1_bin_3) assigned to Mycobacterium were resistant to MLS ( mphA ), rifamycin (ADP ribosylating transferase), aminoglycoside­( aac ( 2 ′)- I ), and tetracycline ( tetV ).…”

New insights into bioaugmented removal of sulfamethoxazole in sediment microcosms: degradation efficiency, ecological risk and microbial mechanisms

“…The sediments for the bioaugmentation microcosm study were collected from an ecological stabilization pond (treating wastewater from a livestock and poultry breeding farm) in Ya’an City, Sichuan Province in November 2020. Detailed information on the stabilization pond sediments was described in our previous studies, including physicochemical properties, SA concentrations, and antibiotic removal capacity [ 29 , 30 ]. After transferring to the laboratory, the sediments were immediately stored at 4 °C before carrying out SA degradation and DNA-SIP experiments.…”

Preparation and Functionalization of Polymers with Antibacterial Properties—Review of the Recent Developments

“…SA are a class of antibiotics that include sulfadiazine, sulfamethazine, and sulfamethoxazole (SMX). One of the possible pathways for the removal of SA is bioaugmentation, which leads to anaerobic degradation of these antibiotics [ 4 ].…”