Ibuprofen Degradation and Associated Bacterial Communities in Hyporheic Zone Sediments.

Malte Posselt,Kirsten Knoop,Cyrus Rutere,Marcus Horn,Adrian Ho

doi:10.3390/microorganisms8081245

Malte Posselt, Kirsten Knoop + Show 3 more

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https://doi.org/10.3390/microorganisms8081245

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Abstract

Ibuprofen, a non-steroidal anti-inflammatory pain reliever, is among pharmaceutical residues of environmental concern ubiquitously detected in wastewater effluents and receiving rivers. Thus, ibuprofen removal potentials and associated bacteria in the hyporheic zone sediments of an impacted river were investigated. Microbially mediated ibuprofen degradation was determined in oxic sediment microcosms amended with ibuprofen (5, 40, 200, and 400 µM), or ibuprofen and acetate, relative to an un-amended control. Ibuprofen was removed by the original sediment microbial community as well as in ibuprofen-enrichments obtained by re-feeding of ibuprofen. Here, 1-, 2-, 3-hydroxy- and carboxy-ibuprofen were the primary transformation products. Quantitative real-time PCR analysis revealed a significantly higher 16S rRNA abundance in ibuprofen-amended relative to un-amended incubations. Time-resolved microbial community dynamics evaluated by 16S rRNA gene and 16S rRNA analyses revealed many new ibuprofen responsive taxa of the Acidobacteria, Actinobacteria, Bacteroidetes, Gemmatimonadetes, Latescibacteria, and Proteobacteria. Two ibuprofen-degrading strains belonging to the genera Novosphingobium and Pseudomonas were isolated from the ibuprofen-enriched sediments, consuming 400 and 300 µM ibuprofen within three and eight days, respectively. The collective results indicated that the hyporheic zone sediments sustain an efficient biotic (micro-)pollutant degradation potential, and hitherto unknown microbial diversity associated with such (micro)pollutant removal.

Highlights

Ibuprofen is a non-steroidal anti-inflammatory drug widely consumed globally for its analgesic, anti-inflammatory, and antipyretic properties
Ibuprofen concentrations were essentially constant in control microcosms containing autoclaved sediment and river water, while ibuprofen was below the detection limit in the unamended microcosms (Figure S1)
Microcosms amended with 200 μM ibuprofen were chosen for in-depth transformation product analysis as representative treatments with a high initial ibuprofen concentration as well as a quick ibuprofen degradation after the fourth refeeding. 1-hydroxyibuprofen, 2-hydroxyibuprofen, 3-hydroxyibuprofen, and carboxyibuprofen were transiently detected in concentrations accounting for less than 1% of the initially supplied ibuprofen, suggesting that such compounds were transformation intermediates (Figure S2)

Summary

Introduction

Ibuprofen is a non-steroidal anti-inflammatory drug widely consumed globally for its analgesic, anti-inflammatory, and antipyretic properties. Low to trace concentrations of the pharmaceutical continue to be detected in the aquatic environment This may be attributed to the continuous input of the compound via raw sewage coupled with a short retention time in the WWTPs, resulting in pseudo-persistence [2]. Ibuprofen was detected in the bile of wild fish caught downstream of a WWTP [5] in addition to the adverse impact on the reproduction of some aquatic organisms, such as zebrafish, planktonic crustaceans, and the Japanese rice fish [6]. Such findings give rise to concerns on the long-term ecological impact of the compound on aquatic ecosystems

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