Biodegradation of oxytetracycline and enrofloxacin by autochthonous microbial communities from estuarine sediments

• Type: Article in International Scientific Journal
• Date: 2019

Authors

Harrabi, M (Author) Other; Alexandrino, DAM (Author) Other; Aloulou, F (Author) Other; Elleuch, B (Author) Other; Liu, B (Author) Other; Jia, ZJ (Author) Other; Marisa M R Almeida (Author) FCUP; Mucha, AP (Author) Other; Carvalho, MF (Author) Other

Journal

Title: Science of the Total Environment

Vol. 648

Pages: 962-972

ISSN: 0048-9697

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 51 Citations

Scopus - 58 Citations

Other information

Authenticus ID: P-00P-GRB

DOI: 10.1016/j.scitotenv.2018.08.193

Abstract (EN): This work investigated the potential of microbial communities native to an estuarine environment to biodegrade enrofloxacin (ENR) and oxytetracycline (OXY). Sediments collected from two sites in the Douro river estuary (Porto, Portugal) were used as inocula for the biodegradation experiments. Experiments were carried out for one month, during which ENR and OXY (1 mgL(-1)) were supplemented individually or in mixture to the cultures at 10-day intervals. Acetate (400 mgL(-1)) was added to the cultures every 3 days to support microbial growth. A series of experimental controls were established in parallel to determine the influence of abiotic breakdown and adsorption in the removal of the antibiotics. Removal of antibiotics was followed by measuring their concentration in the culture medium. Additionally, next-generation sequencing of the 16S rRNA gene amplicon was employed to understand how microbial communities responded to the presence of the antibiotics. At the end of the biodegradation experiments, microbial cultures derived from the two estuarine sediments were able to remove up to 98% of ENR and over 95% of OXY. The mixture of antibiotics did not affect their removal. ENR was removed mainly by biodegradation, while abiotic mechanisms were found to have a higher influence in the removal of OXY. Both antibiotics adsorbed at different extents to the estuarine sediments used as inocula but exhibited a higher affinity to the sediment with finer texture and higher organic matter content. The presence of ENR and OXY in the culture media influenced the dynamics of the microbial communities, resulting in a lower microbial diversity and richness and in the predominance of bacterial species belonging to the phylum Proteobacteria. Therefore, microbial communities native from estuarine environments have potential to respond to the contamination caused by antibiotics and may be considered for the recovering of impacted environments through bioremediation.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11