Overproduction of α-glucosidase in Aspergillus niger transformed with the cloned gene aglA

Abstract

We have transformed an industrial strain, Aspergillus niger GN-3, with the α-glucosidase gene (aglA) from the same strain. Southern hybridization analysis revealed that transformants had multiple copies of the cloned DNA inserted into the host genome. An 11-fold improvement of enzyme production was achieved by transformation with a DNA fragment composed of 1.11 kb of the 5′ noncoding region, 3.12 kb of the coding region containing three introns, and 1.2 kb of the 3′ noncoding region. It was found that the 3′ noncoding region (1.2 kb) was preferable for maximum production of the enzyme in the transformant.