Authors: Simone Larcher Viviane Yargeau
Publish Date: 2011/04/16
Volume: 91, Issue: 1, Pages: 211-218
Abstract
Antibiotic compounds like sulfamethoxazole SMX have become a concern in the aquatic environment due to the potential development of antibacterial resistances Due to excretion and disposal SMX has been frequently detected in wastewaters and surface waters SMX removal in conventional wastewater treatment plants WWTPs ranges from 0 to 90 and there are opposing results regarding its biodegradability at lab scale The objective of this research was to determine the ability of pure cultures of individual and mixed consortia of bacteria Bacillus subtilis Pseudomonas aeruginosa Pseudomonas putida Rhodococcus equi Rhodococcus erythropolis Rhodococcus rhodocrous and Rhodococcus zopfii known to exist in WWTP activated sludge to remove SMX Results showed that R equi alone had the greatest ability to remove SMX leading to 29 removal with glucose and the formation of a metabolite Degradation pathways and metabolite structures have been proposed based on the potential enzymes produced by R equi When R equi was mixed with other microorganisms a positive synergistic effect was not observed and the maximum SMX removal achieved was 5 This indicates that pure culture results cannot be extrapolated to mixed culture conditions and the methodology developed here to study the biodegradability of compounds under controlled mixed culture conditions offers an alternative to conventional studies using pure bacterial cultures or inocula from activated sludge sources consisting of unknown and variable microbial populations
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