Purification a d Characterization f the Overexpressed Aspergilltts oi : yzae Xylanase , XynFl

Xylose in soy sauce mash is released by hydrolyzing the xylan in soy bean and wheat with the xylanolytic enzymes secreted by the shoyu koji mold Aspet:giUus oi yzae. To reduce the xylose content in soy sauce mash, the nucleotide and deduced arnino acid sequences of the aynrv gene, encoding the major xylanase secreted by A. oryzae, have been identified n our previous study.i) Furthermore, repression of the expression of genes encoding xylanolytic enzymes in A. oryzae has been done by introduction of multiple copies of the promoter region from the A, oryzae "ynFl gene.i) However, little is known about the properties of its gene product, XynF1. In this paper we describe the ethcient expression of the aynFl gene under control of A. oi:yzae 7:EFI gene promoter and the characterization of its gene product, XynFl. An ethcient expression system has been developed for A. otyzae KBN616 by use ef the A. oryzae 71EFI gene promoter.2) The 71EFI gene is strong!y expressed even in the presence of glucose where the expression ef a 1arge number of genes involved in the use of less favored car-