Bioaugmentation and rhizosphere-assisted biodegradation as strategies for optimization of the dissipation capacity of biobeds

• Published in: Journal of environmental management Vol. 187; pp. 103 - 110
• Main Authors: Campos, M., Perruchon, C., Karas, P.A., Karavasilis, D., Diez, M.C., Karpouzas, D.G.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2017
• Subjects: 3,5-Dichloraniline (3,5-DCA); Acid Phosphatase - metabolism; Aminoimidazole Carboxamide - analogs & derivatives; Aminoimidazole Carboxamide - metabolism; Aminoimidazole Carboxamide - pharmacokinetics; Aniline Compounds - metabolism; Arthrobacter - metabolism; beta-Glucosidase - metabolism; Bioaugmentation; Biodegradation, Environmental; Farms; Half-Life; Hydantoins - metabolism; Hydantoins - pharmacokinetics; Iprodione; Lolium - metabolism; Microbial abundance; Microbial activity; Pesticides - metabolism; Pesticides - pharmacokinetics; Rhizosphere; Rhizosphere-assisted biodegradation; Waste Management - methods; Microbial activity; 3,5-Dichloraniline (3,5-DCA); Microbial abundance; Bioaugmentation; Rhizosphere-assisted biodegradation; Iprodione
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2016.11.031

Biobeds are on-farm biodepuration systems whose efficiency rely on their high pesticide biodegradation capacity. We evaluated two optimization strategies, bioaugmentation and/or rhizosphere-assisted biodegradation, to maximize the dissipation capacity of biobeds. Iprodione was used as a model pesticide. Its dissipation and metabolism was determined in a biobed packing material inoculated with an iprodione-degrading Arthrobacter strain C1 (bioaugmentation, treatments B+C1) and/or seeded with ryegrass (rhizosphere-assisted biodegradation, treatments B+P). The impact of those strategies on the activity and composition of the microbial community was determined. Bioaugmentation accelerated the dissipation of iprodione which was further enhanced in the bioaugmented, rhizosphere-assisted treatment (treatment B+P+C1, Half-life (DT50) = 3.4 d), compared to the non-bioaugmented, non rhizosphere-assisted control (DT50 = 9.5 d, treatment B). Bioaugmentation resulted in the earlier formation of intermediate formation of metabolites I (3,5-dichlorophenyl-carboxamide), II (3,5-dichlorophenylurea acetate) and 3,5-dichloroaniline (3,5-DCA). The latter was further dissipated by the indigenous microbial community. Acid phosphatase (AP) and β-glucosidase (GLU) were temporarily stimulated in rhizosphere-assisted treatments, whereas a stimulation of the fluorescein diacetate (FDA) hydrolytic activity in the bioaugmented treatments coincided with the hydrolysis of iprodione. q-PCR showed that changes in the abundance of alpha-proteobacteria and firmicutes was driven by the presence of rhizosphere while bioaugmentation had no significant effect. [Display omitted] •Bioaugmentation and rhizosphere-assisted biodegradation optimize biobeds efficiency.•Bioaugmentation accelerated the transformation of iprodione and its metabolites.•Rhizosphere-assisted biodegradation magnified the positive effect of bioaugmentation.•Rhizosphere-assisted biodegradation induced changes in the microbial community.•Bioaugmentation did not affect the microbial community of biobed packing material.