Bioattenuation of Detergent Plant Effluents Enhanced via Single Microbial Augmentations

Abstract

Due to natural attenuation, anionic detergents in surface waters are not inferred as big environmental issues. However, the effluents from large industrial areas with high detergent concentrations can have significant local impacts. These circumstances can be diminished by using efficient detergent-degrading bacterial isolates through bioaugmentation. In this study, detergent plant effluents were analysed by using a methylene blue active substance assay to determine detergent content during natural attenuation processes, and after single augmentations of 12 anionic detergent-degrading bacterial isolates with high detergent tolerating abilities in batch microcosms. Maximum bioattenuation of detergents was determined as 56 % after 66 h incubation under the conditions that mimicked the natural environment. Bioattenuation was enhanced as much as 83 and 91 % in 78 h incubation time through single microbial augmentations of filter-sterilized and non-sterilized effluents, respectively. Eight Pseudomonas and one Aeromonas species were found to be highly competitive by showing high biodegradation abilities in pure culture experiments as well as enhancing degradation of detergents in both filter-sterilized and nonsterilized effluents through their single augmentations. Although remaining three isolates, namely Pseudomonas fluorescens SDS6, P. resinovorans SDS10-2, and P. corrugata SDS10-3 displayed lower degrading abilities in pure culture experiments than the natural attenuation, they later turned out to be actively enhancing the degradation of detergents during their single augmentations.