REGULATION OF ALPHA-AMYLASE FORMATION IN ASPERGILLUS-ORYZAE AND ASPERGILLUS-NIDULANS TRANSFORMANTS

Aspergillus oryzae was grown in a minimal medium supplemented with nine different carbon sources. Alpha-Amylase formation was induced by starch and maltose. With glucose, no carbon catabolite repression was observed, but surprisingly alpha-amylase production was induced; all other tested carbon sources failed to influence alpha-amylase synthesis. Simultaneous cultivation with two different carbon sources confirmed this alpha-amylase regulation. Northern blot analysis showed that alpha-amylase gene expression was controlled at the level of transcription. For further characterization of alpha-amylase expression, Aspergillus nidulans was transformed by the amyl gene of A. oryzae. The regulation of alpha-amylase formation in three analyzed transformants by different carbon sources was comparable to that of the A. oryzae wildtype.