Isolation of a bacterial consortium able to degrade the fungicide thiabendazole: the key role of a Sphingomonas phylotype.
Thiabendazole (TBZ) is a fungicide used in fruit-packaging plants. Its application leads to the production of wastewaters requiring detoxification. In the absence of efficient treatment methods, biological depuration of these effluents could be a viable alternative. However, nothing is known regarding the microbial degradation of the recalcitrant and toxic to aquatics TBZ. We report the isolation, via enrichment cultures from a polluted soil, of the first bacterial consortium able to rapidly degrade TBZ and use it as a carbon source. Repeated efforts using various culture-dependent approaches failed to isolate TBZ-degrading bacteria in axenic cultures. Denaturating gradient gel electrophoresis (DGGE) and cloning showed that the consortium was composed of α-, β- and γ-Proteobacteria. Culture-independent methods including antibiotics-driven selection with DNA/RNA-DGGE, q-PCR and stable isotope probing (SIP)-DGGE identified a Sphingomonas phylotype (B13) as the key degrading member. Cross-feeding studies with structurally related chemicals showed that ring substituents of the benzimidazole moiety (thiazole or furan rings) favoured the cleavage of the imidazole moiety. LC-MS/MS analysis verified that TBZ degradation proceeds via cleavage of the imidazole moiety releasing thiazole-4-carboxamidine, which was not further transformed, and the benzoyl moiety, possibly as catechol, which was eventually consumed by the bacterial consortium as suggested by SIP-DGGE.
Department of Biochemistry and Biotechnology, University of Thessaly, Laboratory of Plant and Environmental Biotechnology, Viopolis, 41500, Larissa, Greece.
Chiara
C
Perruchon
Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, 04318, Leipzig, Germany.|German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103, Leipzig, Germany.
Antonis
A
Chatzinotas
Agricultural Research Institute of Cyprus, Leukosia, Cyprus.
Michalis
M
Omirou
Centre for Environmental Risk Assessment and Remediation, Mawson Lakes Campus, University of South Australia, Future Industries Institute, Adelaide, Australia.
Sotirios
S
Vasileiadis
School of Agriculture, Laboratory of Pesticide Science, Aristotle University of Thessaloniki, Thessaloniki, Greece.
Urania
U
Menkissoglou-Spiroudi
Department of Biochemistry and Biotechnology, University of Thessaly, Laboratory of Plant and Environmental Biotechnology, Viopolis, 41500, Larissa, Greece. dkarpouzas@bio.uth.gr.
Dimitrios G
DG
Karpouzas
D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000378:metabolism*; D001711:Biotransformation; D002244:Carbon / Q000378:metabolism; D002853:Chromatography, Liquid; D003001:Cloning, Molecular; D058645:Denaturing Gradient Gel Electrophoresis; D005659:Fungicides, Industrial / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D059013:Microbial Consortia; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D053719:Tandem Mass Spectrometry; D013827:Thiabendazole / Q000378:metabolism*
D005659:Fungicides, Industrial; D002244:Carbon; D013827:Thiabendazole
Fruit-packaging industry; Pesticide biodegradation; SIP-DGGE; Sphingomonas; Thiabendazole; Wastewaters