Journal of Microbiology

Purification and Characteristics of Glucoamylase in Aspergillus oryzae NR 3-6 Isolated from Traditional Korean Nuruk: Yu, Tae Shick , Kim, Tae Hyoung , Joo, Chong Yoon; J. Microbiol. 1999;37(2):80-85.

Abstract: The purification system of glucoamylase (glucan 1,4-α-glucosidase, EC 3. 2. 1. 3), some characteristics of the purified enzyme and hydrolysis rate of various raw starch were investigated through several experiments. The enzyme was produced on a solid, uncooked wheat bran medium of Aspergillus oryzae NR 3-6 isolated from traditional Korean Nuruk. The enzyme was homogeneously purified 6.8-fold with an overall yield of 28.3% by the criteria of disc- and SDS-polyacrylamide gel electrophoresis. The molecular weight was estimated to be 48 kDa by SDS-PAGE. The optimum temperature and pH were 55℃ and 4.0, respectively. The enzyme was stable at a pH range of 3.0∼10.0 and below 45℃. Enzyme activity was inhibited about 27% by 1mM Hg^2+. The hydrolysis rate of raw wheat starch was shown to be 17.5-fold faster than the hydrolysis rate of soluble starch. The purified enzyme was identified as glucoamylase because the product of soluble starch by the purified enzyme was mainly glucose by thin layer chromatography.

Monascus Red Pigment Overproduction by Coculture with Recombinant Saccharomyces cerevisiae Secreting Glucoamylase: Ho-Soo Lim , Seung-Ku Yoo , Chul-Soo Shin , Young-Min Hyun; J. Microbiol. 2000;38(1):48-51.

Abstract: In liquid cultures using sucrose media, the coculture of Monascus with recombinant Saccharomyces cerevisiae expressing the glucoamylase gene from Aspergillus niger enhanced red pigment production by approx. 19%, compared with the coculture of wild type S. cerevisiae. Coculture with recombinant S. cerevisiae was more effective than with wild type S. cerevisiae for Monascus red pigment production. Cocultures of Monascus with commercial amylases of Aspergillus also induced high production of pigment and morphological changes in a solid culture using sucrose media.

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