Isolation, characterization and industrial application of a Cladosporium herbarum fungal strain able to degrade the fungicide imazalil

Christina V Papazlatani; Maria Kolovou; Elisabeth E Gkounou; Konstantinos Azis; Zografina Mavriou; Stefanos Testembasis; George S Karaoglanidis; Spyridon Ntougias; Dimitrios G Karpouzas

doi:10.1016/j.envpol.2022.119030

Isolation, characterization and industrial application of a Cladosporium herbarum fungal strain able to degrade the fungicide imazalil

Environ Pollut. 2022 May 15:301:119030. doi: 10.1016/j.envpol.2022.119030. Epub 2022 Feb 18.

Authors

Christina V Papazlatani¹, Maria Kolovou¹, Elisabeth E Gkounou¹, Konstantinos Azis², Zografina Mavriou², Stefanos Testembasis³, George S Karaoglanidis³, Spyridon Ntougias², Dimitrios G Karpouzas⁴

Affiliations

¹ University of Thessaly, Department of Biochemistry and Biotechnology, Laboratory of Plant and Environmental Biotechnology, Viopolis, 41500, Larissa, Greece.
² Democritus University of Thrace, Department of Environmental Engineering, Laboratory of Wastewater Management and Treatment Technologies, Vas. Sofias 12, 67132, Xanthi, Greece.
³ Aristotle University of Thessaloniki, Department of Agriculture, Plant Pathology Laboratory, University Campus, 54124, Thessaloniki, Greece.
⁴ University of Thessaly, Department of Biochemistry and Biotechnology, Laboratory of Plant and Environmental Biotechnology, Viopolis, 41500, Larissa, Greece. Electronic address: dkarpouzas@uth.gr.

PMID: 35189300
DOI: 10.1016/j.envpol.2022.119030

Abstract

Imazalil (IMZ) is an imidazole fungicide commonly used by fruit-packaging plants (FPPs) to control fungal infections during storage. Its application leads to the production of pesticide-contaminated wastewaters, which, according to the European Commission, need to be treated on site. Considering the lack of efficient treatment methods, biodepuration systems inoculated with tailored-made inocula specialized on the removal of such persistent fungicides appear as an appropriate solution. However, nothing is known about the biodegradation of IMZ. We aimed to isolate and characterize microorganisms able to degrade the recalcitrant fungicide IMZ and eventually to test their removal efficiency under near practical bioengineering conditions. Enrichment cultures from a soil receiving regular discharges of effluents from a FPP, led to the isolation of a Cladosporium herbarum strain, which showed no pathogenicity on fruits, a trait essential for its biotechnological exploitation in FPPs. The fungus was able to degrade up to 100 mg L^-1 of IMZ. However, its degrading capacity and growth was reduced at increasing IMZ concentrations in a dose-dependent manner, suggesting the involvement of a detoxification rather than an energy-gain mechanism in the dissipation of IMZ. The isolate could tolerate and gradually degrade the fungicides fludioxonil (FLD) and thiabendazole (TBZ), also used in FPPs and expected to coincide alongside IMZ in FPP effluents. The capacity of the isolate to remove IMZ in a practical context was evaluated in a benchtop immobilized-cell bioreactor fed with artificial IMZ-contaminated wastewater (200 mg L^-1). The fungal strain established in the reactor, completely dominated the fungal community and effectively removed >96% of IMZ. The bioreactor also supported a diverse bacterial community composed of Sphingomonadales, Burkholderiales and Pseudomonadales. Our study reports the isolation of the first IMZ-degrading microorganism with high efficiency to remove IMZ from agro-industrial effluents under bioengineering conditions.

Keywords: Agro-industrial effluents; Biodegradation; Cladosporium herbarum; Fruit-packaging plants; Imazalil; Immobilized cell bioreactor.

MeSH terms

Cladosporium
Fungi / metabolism
Fungicides, Industrial* / metabolism
Imidazoles

Substances

Fungicides, Industrial
Imidazoles
enilconazole

Supplementary concepts

Cladosporium herbarum