Isolation, characterization and industrial application of a Cladosporium herbarum fungal strain able to degrade the fungicide imazalil. (15th May 2022)

• Record Type: Journal Article
• Authors: Papazlatani, Christina V.; Kolovou, Maria; Gkounou, Elisabeth E.; Azis, Konstantinos; Mavriou, Zografina; Testembasis, Stefanos; Karaoglanidis, George S.; Ntougias, Spyridon; Karpouzas, Dimitrios G.
• Is Part Of: Environmental pollution. Volume 301(2022)
• Publication Date: 2022-05-15
• Subjects: Imazalil -- Biodegradation -- Cladosporium herbarum -- Immobilized cell bioreactor -- Fruit-packaging plants -- Agro-industrial effluents; FPP fruit packaging plant -- IMZ imazalil -- MSMN minimal salt medium with nitrogen -- PDB potato dextrose broth -- TBZ thiabendazole -- FLD fludioxonil -- OPP ortho-phenyl phenol -- IPR iprodione -- 3, 5-DCA 3, 5 dichloro-aniline; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2022.119030
• Languages: English
• ISSNs: 0269-7491

Abstract

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. Graphical abstract: Image 1 Highlights: The first IMZ-degrading microorganism, a Cladosporium herbarum strain, was isolated from soil. C. herbarum degraded up to 100 mg L −1 of IMZ through a non-energy-gain process. C. herbarum was able to degrade other fungicides used in fruit-packaging plants. C. herbarum established and efficiently removed IMZ from wastewater in a benchtop bioreactor. C. herbarum is a highly potent inoculum for the biological treatment of wastewaters from FPPs.