ORGANOHALOGEN PRODUCTION IS A UBIQUITOUS CAPACITY AMONG BASIDIOMYCETES

Several species of basidiomycetes are capable of producing de novo hig h concentrations of chloroaromatic metabolites. However, the extent to which basidiomycetes contribute to the natural pool of adsorbable org anic halogen (AOX) found in the environment is unknown yet. The purpos e of this study was to determine the ubiquity of organohalogen product ion among basidiomycetes and to determine maximal specific organohalog en production rates. Finally, the fate of the fungal chloroaromatic co mpounds in the environment was studied. A total of 191 fungal strains were tested for AOX production when grown on defined liquid medium. Ap proximately 50% of the strains tested and 55% of the genera tested pro duced AOX. Organohalogen production seemed to be a ubiquitous capacity among basidiomycetes. Many highly ecologically significant fungal spe cies were identified among the moderate and high producers. Although i t was found that the final AOX concentrations produced by Hypholoma fa sciculare was strongly influenced by the substrate used, all maximal s pecific AOX production rates on different substrates were in the same order of magnitude. Seven new species and four new genera of basidiomy cetes could be added to the list of known chlorinated anisyl metabolit es (CAM) producing basidiomycetes. In degradation studies of the major fungal metabolite 3,5-dichloro-anisyl alcohol, it was found that in f orest soils there seems to be ubiquitous mineralizing capacity for thi s chlorinated aromatic compound. It was found that Burkholderia cepaci a was responsible for the fast degradation of the fungal compound in t he oak forest soils. (C) 1998 Elsevier Science Ltd. All rights reserve d.