A novel and affordable bioaugmentation strategy with microbial extracts to accelerate the biodegradation of emerging contaminants in different media

Abstract

This study describes a new bioaugmentation alternative based on the application of aqueous aerated extracts from a biomixture acclimated with ibuprofen, diclofenac and triclosan. This bioaugmentation strategy was assayed in biopurification systems (BPS) and in contaminated aqueous solutions to accelerate the removal of these emerging contaminants. Sterilized extracts or extracts from the initial uncontaminated biomixture were used as controls. In BPS, the dissipation of 90% of diclofenac and triclosan required, respectively, 60 and 108 days less than in the controls. The metabolite methyl-triclosan was determined at levels 12 times lower than in controls. In the bioaugmented solutions, ibuprofen was almost completely eliminated (99%) in 21 days and its hydroxylated metabolites were also determined to be at lower levels than in the controls. The plasmidome of acclimated biomixtures and its extract appeared to maintain certain types of plasmids but degradation related genes became less evident. Several dominant OTUs found in the extract identified as Flavobacterium and Fluviicola of the phylum Bacteroidetes, Thermomicrobia (phylum Chloroflexi) and Nonomuraea (phylum Actinobacteria), may be responsible for the enhanced dissipation of these contaminants. This bioaugmentation strategy represents an advantageous tool to facilitate in situ bioaugmentation.