Copper ion (Cu2+) is involved in the transcription of the tyrosinase-encoding melB gene of Aspergillus oryzae in solid-state culture

Abstract

ABSTRACT In Aspergillus oryzae, the tyrosinase-encoding gene melB causes undesirable browning of sake and sake lees. This gene is known to be expressed specifically in solid-state culture; however, its expression mechanisms remain unknown. Here, we evaluated the possible factors affecting the transcription of melB and found that the copper ion (Cu2+) significantly enhanced the transcription level of melB in solid-state culture.