Effect of tyrosinase inhibitors on Tuber borchii mycelium growth in vitro

This paper reports the effect of the tyrosinase (monophenol o-diphenol:oxyg en oxidoreductase; EC 1.14.18.1) inhibitors diethyldithiocarbamate (DETC), L-tropolone, kojic acid, phenylthiourea (PTU) and L-mimosine on the in vitr o growth of Tuber borchii (a white truffle) mycelium. A significant inhibit ory effect on mycelium growth was observed for DETC, PTU and L-tropolone (0 % growth compared to control at 100 mu g ml(-1) DETC, PTU and L-tropolone a nd at 10 mu g ml(-1) DETC and L-tropolone). As a comparison the action of t he same inhibitors was also tested on the growth and pigmentation of the mo uld Cladosporium sphaerospermum. In the presence of CuSO4 10(-6) M T. borch ii mycelium acquired pigmentation (as rounded aggregates compared to contro l revealed by SEM microscopy). Tyrosinase activity in the extract from T. b orchii mycelium (18-day culture) was detected spectrophotometrically. (C) 1 999 Federation of European Microbiological Societies. published by Elsevier Science B.V. All rights reserved.