BREAKDOWN MECHANISMS FOR CLASSIC ORGANIC WOOD PRESERVATIVES

Derek F. WALLACE
Dr. - Timber Technology, Imperial College, London
Address: Sir Alexander Fleming Building, Imperial College, London, UK SW7 2AZ
Tel: +44 (0)2075945391. Fax: +44 (0)2075945390. E-mail: derek_f_wallace@yahoo.co.uk

David J. DICKINSON
Dr. - Timber Technology, Imperial College, London
Address: Sir Alexander Fleming Building, Imperial College, London, UK SW7 2AZ
Tel: +44 (0)2075945391. Fax: +44 (0)2075945390. E-mail: d.dickinson@imperial.ac.uk

Abstract: The fungicides chlorothalonil, IPBC, tebuconazole and a developmental biocide, were all found to be degraded by a proteobacterial isolate, with this effect being mediated by an extracellular factor. From a series of in vitro studies, the tri-peptide glutathione was identified as the moiety associated with detoxification, with the electrophilicity of the biocide being critical for degradation. By formulating the biocide with a chemical of higher electrophilicity, it was shown to be possible to protect the developmental biocide from the degradative effects of glutathione. We consider that this may represent a means by which organic wood preservatives susceptible to microbial degradation can be stabilised, heralding a new generation of wood preservative formulations.

Key words: organic biocides, microbial detoxification, glutathione.