The effects of aeration and veratryl alcohol on the production of two laccases by the ascomycete Botryosphaeria sp.

The ascomycete, Botryosphaeria sp, produced two extracellular constitutive laccases (PPO-I and PPO-II) active toward the substrates: 2, 2(I)-azino-bis (3-ethyl-benzthiazoline-6-su acid) [ABTS], and 2,6-dimethoxyphenol (DMP), r espectively. The production of both laccases increased when the fungal isol ate was grown in the presence of veratryl alcohol, and resulted in optimal laccase production (100-and 25- fold, respectively) at 40 mM. The effect of aeration on growth and laccase production was studied in baffled flasks, a nd showed that aeration of the cultures increased the production of both en zymes 4-5 fold in the presence of veratryl alcohol. Both laccases were susc eptible to inhibition by azide, acetate and chloride anions. Veratryl alcoh ol inhibited the laccase-catalyzed polymerization of DMP. Growing cultures of Botryosphaeria sp. produced an exopolysaccharide of the beta -glucan typ e whose synthesis was depressed when grown in the presence of veratryl alco hol. (C) 2001 Elsevier Science Inc. All rights reserved.