www.hu-srb-ipa.com. LAC RE MED. Development of an enzymological (laccase-based) remediation product and technology. Background:
Development of an enzymological (laccase-based) remediation product and technology
Pesticides and their degradation products frequently contaminate ground or surface water and soils. This contamination should be prevented as far as possible, not only because of their direct toxicity to man, but also because of their influence on the water biocenosis and their potential accumulation in the food-chain. Many pesticides in intact form, or their degradation products, have carcinogenic, mutagenic, teratogenic immuno-modulating and endocrine disrupting properties. Some pesticides (and their degradation products) frequently used in Serbia and Hungary are known to cause human health problems. The pesticide active ingredients with high risk factors belong to the anilinogenic and phenoligenic ones, the two groups which microbial degradation results in chlorinated highly toxic aniline and phenol derivatives. The anilinogenic ones are the followings: diuron, linuron, propham, chlorpropham, chlorotoluron, diflubenzuron and dimethachlor herbicides; the phenoligenic ones are the followings: 2,4-D and MCPA herbicides.
Accelerated, complete degradation of all these herbicides and the accumulating catabolic intermediate compounds in agricultural soils and in surface waters would be highly desirable, but most of these molecules are highly resistant to microbial degradation.
Extracellular fungal laccases, however, are able to oxidize and polymerize these highly toxic compounds into less soluble, high molecular mass compounds that may be easily removed from water by sedimentation or filtration; in soils, enzymes detoxify the mentioned pollutants by coupling them onto humic acids (natural macromolecules-constituents of soil humus), immobilizing them and preventing their leaching.
Many filamentous fungi produce extracellular laccases on cheap substrates. The well known laccase producers are the mushrooms Agaricus and Pleurotus, and some soil moulds e.g. Cladosporium, Alternaria and Botrytis.
Department of Microbiology, Faculty of Science
and Informatics, University of Szeged
Közép fasor 52., H-6726 Szeged, Hungary
Contact: Prof. Dr. Csaba Vágvölgyi
E mail: [email protected]
Faculty of Technology, University of Novi Sad
Bulevar cara Lazara 1, 21000 Novi Sad, Serbia
Contact: Prof. Prof. Dr. Biljana Škrbić
E-mail: [email protected]
The aim of the project is the development of a cheap microbial laccase mixture, which able to detoxify a wide range of xenobiotics belonging to the groups of phenol and aniline derivatives.
1. Isolation of distinct laccase producing filamentous fungi from soil and air on specific detection-isolation media.
2. Investigating of culture media dependence of laccase producing activity of the best strains.
3. Identification of the best laccase producers.
4. Investigation and determination of the substrate spectra of the distinct fungal laccases.
5. Investigation of activity levels of diluted laccase containing ferment broths on distinct pollutants.
6. Investigation of the stability (“half life times”) of laccases in distinct water and soil types.
7. Comparative investigations in laboratory of detoxifying activity of fungal laccases and their mixtures on distinct phenol and aniline derivatives in water and soil microcosms systems.
8. In field investigations of the activity of laccases on 2,4-dichlorophenol and 3,4-dichloroaniline in the soils of distinct plant cultures.
This document has been produced with the financial assistance of the European Union. The content of the document is the sole responsibility of the Department of Microbiology, Faculty of Sciences, University of Szeged, Hungary and the Faculty of Environmental Sciences, Educons University, Sremska Kamenica, Serbiaand can under no circumstances be regarded as reflecting the position of the European Union and/or the Managing Authority.