• Journal of Microbiology and Biotechnology
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• v.11 no.6
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• pp.1066-1070
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• 2001

The PhyA gene, encoding myo-inositol hexakisphosphate phosphohydrolase in Aspergillus niger var. awamori (wild-type), was cloned and sequenced. The cDNA was overexpressed by a multicopy gene expression system in Pichia pastoris KM71. Recombinant, wild-type and commercial phytase from Aspergilus ficuum NRRL 3135 (Natuphos) were purified. The PhyA gene of Aspergillus niger var awamori showed perfect homology to the phytase of Aspergillus ficcum and $97\%$ homology to A. niger var awamori (L02421). Wild-type phytase was highly glycosylated and more thermostable than the other two, while deglycosylated farms of three phytases showed identical molecular weight, 507 kDa. After heating at $80^{\circ}C$, wild-type, commercial, and recombinant phytases retained $57\%, 32%,\;and\;8\%$ of their original activities, respectively. In conclusion, glycosylation plays a key role in the thermostability of phytase and its enzymatic characterization.

• The Korean Journal of Mycology
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• v.12 no.1
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• pp.21-26
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• 1984

Aspergillus awamori which produces glucoamylase was cultivated in the starch-Czapek-­Dox's medium in which sucrose was depleted. A rapid method for identification and assay of glucoamylase produced by the A. awamori in the culture was established by the use of the glucose oxidase. The levels of glucose derived from the breakdown of the starch medium were assayed by using glucose oxidase, which was proved to be effective in the screening of glucoamylase-producing fungi in terms of rapid and simple determination. After the cellulose acetate electrophoresis of the precipita ted culture broth, the glucoamylase band in the gel was contacted with 2% starch solution with glucose oxidase, and then color reaction was occurred. Also this method could be effective to identify rapidly the fungal glucoamylase.