title: Evaluation of Arthrobacter aurescens Strain TC1 as Bioaugmentation Bacterium in Soils Contaminated with the Herbicidal Substance Terbuthylazine.
abstract: In the last years the chloro-s-triazine active substance terbuthylazine has been increasingly used as an herbicide and may leave residues in the environment which can be of concern. The present study aimed at developing a bioaugmentation tool based on the soil bacterium Arthrobacter aurescens strain TC1 for the remediation of terbuthylazine contaminated soils and at examining its efficacy for both soil and aquatic compartments. First, the feasibility of growing the bioaugmentation bacterium inocula on simple sole nitrogen sources (ammonium and nitrate) instead of atrazine, while still maintaining its efficiency to biodegrade terbuthylazine was shown. In sequence, the successful and quick (3 days) bioremediation efficacy of ammonium-grown A. aurescens TC1 cells was proven in a natural soil freshly spiked or four-months aged with commercial terbuthylazine at a dose 10× higher than the recommended in corn cultivation, to mimic spill situations. Ecotoxicity assessment of the soil eluates towards a freshwater microalga supported the effectiveness of the bioaugmentation tool. Obtained results highlight the potential to decontaminate soil while minimizing terbuthylazine from reaching aquatic compartments via the soil-water pathway. The usefulness of this bioaugmentation tool to provide rapid environment decontamination is particularly relevant in the event of accidental high herbicide contamination. Its limitations and advantages are discussed.
authors.affiliation: iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico (IST), Universidade de Lisboa (UL), Lisboa, Portugal.
authors.forename: Vera P
authors.initials: VP
authors.lastname: Silva
authors.affiliation: CFE-Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Coimbra, Portugal.
authors.forename: Matilde
authors.initials: M
authors.lastname: Moreira-Santos
authors.affiliation: iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico (IST), Universidade de Lisboa (UL), Lisboa, Portugal.
authors.forename: Carla
authors.initials: C
authors.lastname: Mateus
authors.affiliation: CFE-Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Coimbra, Portugal.
authors.forename: Tânia
authors.initials: T
authors.lastname: Teixeira
authors.affiliation: CFE-Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Coimbra, Portugal.
authors.forename: Rui
authors.initials: R
authors.lastname: Ribeiro
authors.affiliation: iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico (IST), Universidade de Lisboa (UL), Lisboa, Portugal.|Department of Bioengineering, IST, UL, Lisboa, Portugal.
authors.forename: Cristina A
authors.initials: CA
authors.lastname: Viegas
mesh_terms: D001173:Arthrobacter / Q000254:growth & development* / Q000378:metabolism; D001673:Biodegradation, Environmental; D006540:Herbicides / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D058086:Microalgae / Q000187:drug effects; D009584:Nitrogen / Q000378:metabolism; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D014227:Triazines / Q000378:metabolism* / Q000633:toxicity
chemical_list: D006540:Herbicides; D012989:Soil Pollutants; D014227:Triazines; C037565:terbutylazine; D009584:Nitrogen