The potential of some substrates to induce tannase activity
was measured (Table 4). The Aspergillus sp. GM4
was initially cultured in modified Adams medium containing
2% (w/v) glucose, and a basal tannase activity
(1.29 U/mg) was observed. The mycelia mass was transferred
to modified Adams medium containing gallic acid,
green tea, methyl gallate, tannic acid or glucose to examine
induction or repression by these carbon sources.