Letters in Applied Microbiology 1996, 23, 93-96 Veratryl alcohol as an inducer of laccase by an ascomycete, Botryosphaeria sp., when screened on the polymeric dye Poly R-478 A.M. Barbosa 1 , R.F.H. Dekker and G.E. St. Hardy School of Biological and Environmental Sciences, Biotechnology Program, Murdoch University, Murdoch, 6150, W.A., Australia, and 1 Universidade Estadual de Londrina, Depto. de Bioquimica-CCE, Londrina, Paraná, Brazil JIP/123: received 19 December 1995 and accepted 15 January 1996 A.M. BARBOSA, R.F.H. DEKKER AND G.E. St. J. HARDY. 1996. Forty fungi isolated from diverse environments in Western Australia were screened for ligninolytic activity based on in vivo decolourization of the polymeric dye Poly R-478. Three isolates identified as Aspergillus, Botryosphaeria , and Coniochaeta species were selected for further studies. The Botryosphaeria and Coniochaeta isolates were found to produce laccase constitutively in submerged culture when grown on glucose or on ryegrass seed by solid state fermentation.. A comparison of the three isolates grown on glucose in the presence of 40 mmol l -1 3,4-dimethoxybenzyl (veratryl) alcohol showed that only the Botryosphaeria isolate produced laccase, and the laccase activity was 115 fold higher than on glucose alone. Correspondence to: Dr. R.F.H. Dekker, School of Biological and Environmental Sciences, Murdoch University, Murdoch, 6150, W.A., Australia (email: dekker@central.murdoch.edu.au ). INTRODUCTION The decolourization of polymeric dyes has proved to be a good indicator of the initial transformation of lignin (Glenn and Gold 1983; Gold et al. 1988) and toxic xenobiotic compounds (Field et al. 1993). Basidiomycetes causing white rot of wood have been intensively studied as being typically ligninolytic (Higuchi 1993), and they constitute a promising group of microorganisms for application in the bioremediation of recalcitrant xenobiotic compounds (Field et al. 1993). A full understanding of the enzymes involved in the primary attack of the complex phenolic polymer constituting lignin is still incomplete. Such enzymes include oxidases and peroxidases that are produced extracellularly by Phanerochaete chrysosporium and other white rot fungi described as involved in lignin degradation (Fiechter 1993). Laccase (EC 1.10.3.2; benzenediol:oxygen oxidoreductase) has been demonstrated in some basidiomycete and ascomycete fungi (Thurston 1994; Yaropolov et al. 1994). Many white rot fungi, with the notable exception of P. chrysosporium, produce extracellular laccases. This enzyme is believed to be involved in lignin degradation (Bourbonnais and Paice 1989; Gold and Alic 1993); in the detoxification of phenolic compounds (Bollag et al. 1988), and also in the dechlorination of some chlorophenolic compounds (Roy-Arcand and Archibald 1991). Consequently, microorganisms, which are laccase producers could also be useful in bioremediation of xenobiotic compounds. 3,4-Dimethoxybenzyl (veratryl) alcohol is a secondary metabolite