DENITRIFICATION BY YEASTS AND OCCURRENCE OF CYTOCHROME P450NOR IN TRICHOSPORON-CUTANEUM

Yeasts of various genera were screened for denitrifying activity, and several yeast strains such as Trichosporon cutaneum, Fellomyces fuzhou ensis, and Candida sp. were found to exhibit distinct activities to co nvert nitrite to nitrous oxide. Dissimilatory nitrite reductase (Nir) or nitric oxide reductase (Nor) activities were detected in the cell-f ree extracts of these yeasts. Spectrophotometric as well as Western bl ot analyses showed that T. cutaneum contains Nor of the cytochrome P45 0 type. This is the first report that shows that denitrification is al so distributed among yeasts although their systems are incomplete, onl y capable of reducing nitrite to nitrous oxide. (C) 1998 Federation of European Microbiological Societies. Published by Elsevier Science B.V . All rights reserved.