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https://hdl.handle.net/10216/120534
Author(s): | Alexandrino D.A.M. Mucha A.P. Almeida C.M. Gao W. Jia Z. Carvalho M.F. |
Title: | Biodegradation of the veterinary antibiotics enrofloxacin and ceftiofur and associated microbial community dynamics |
Publisher: | Elsevier |
Issue Date: | 2017 |
Abstract: | Fluoroquinolones and cephalosporins are two classes of veterinary antibiotics arising as pollutants of emerging concern. In this work, the microbial degradation of two representative antibiotics of both these classes, enrofloxacin (ENR) and ceftiofur (CEF), is reported. Biodegradation of the target antibiotics was investigated by supplementing the culture medium with ENR and CEF, individually and in mixture. Microbial inocula were obtained from rhizosphere sediments of plants derived from experimental constructed wetlands designed for the treatment of livestock wastewaters contaminated with trace amounts of these antibiotics. Selected microbial inocula were acclimated during a period of 5 months, where the antibiotics were supplemented every three weeks at the concentration of 1 mg L− 1, using acetate as a co-substrate. After this period, the acclimated consortia were investigated for their capacity to biodegrade 2 and 3 mg L− 1 of ENR and CEF. Complete removal of CEF from the inoculated culture medium was always observed within 21 days, independently of its concentration or the concomitant presence of ENR. Biodegradation of ENR decreased with the increase in its concentration in the culture medium, with defluorination percentages decreasing from ca. 65 to 4%. Ciprofloxacin and norfloxacin were detected as biodegradation intermediates of ENR in the microbial cultures supplemented with this antibiotic, indicating that defluorination of at least part of ENR in these cultures is not an immediate catabolic step. Abiotic mechanisms showed high influence in the removal of CEF, affecting less ENR degradation. The acclimation process with the target antibiotics led to significant shifts in the structure and diversity of the microbial communities, predominantly selecting microorganisms belonging to the phyla Proteobacteria (e.g. Achromobacter, Variovorax and Stenotrophomonas genera) and Bacteroidetes (e.g. Dysgonomonas, Flavobacterium and Chryseobacterium genera). The results presented in this study indicate that biodegradation can be an important mechanism for the environmental removal of the tested compounds. © 2016 Elsevier |
Subject: | Agriculture Antibiotics Drug products Microorganisms Soils Wastewater treatment Wetlands Ceftiofur Constructed wetlands Enrofloxacin Metagenomics Microbial communities Microbial community dynamics Microbial degradation Veterinary antibiotic Biodegradation acetic acid ceftiofur ciprofloxacin enrofloxacin norfloxacin veterinary drug antibiotics biodegradation community dynamics concentration (composition) genomics microbial community abiotic stress acclimatization Article Bacteroidetes catabolism community dynamics community structure constructed wetland controlled study culture medium defluorination livestock metagenomics microbial community microbial degradation microbial diversity nonhuman Proteobacteria rhizosphere inoculation waste component removal waste water water contamination Achromobacter Bacteroidetes Chryseobacterium Dysgonomonas Flavobacterium Proteobacteria Stenotrophomonas Variovorax |
URI: | https://hdl.handle.net/10216/120534 |
Source: | Science of the Total Environment, vol. 581-582, p. 359-368 |
Document Type: | Artigo em Revista Científica Internacional |
Rights: | restrictedAccess |
Appears in Collections: | CIIMAR - Artigo em Revista Científica Internacional |
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