Degradation of raw starch granules by alpha-amylase purified from culture of Aspergillus awamori KT-11.
Raw-starch-digesting alpha-amylase (Amyl III) was purified to an electrophoretically pure state from the extract of a koji culture of Aspergillus awamori KT-11 using wheat bran in the medium. The purified Amyl III digested not only soluble starch but also raw corn starch. The major products from the raw starch using Amyl III were maltotriose and maltose, although a small amount of glucose was produced. Amyl III acted on all raw starch granules that it has been tested on. However, it was considered that the action mode of the Amyl III on starch granules was different from that of glucoamylase judging from the observation of granules under a scanning electron microscope before and after enzyme reaction, and also from the reaction products. Glucoamylase (GA I) was also isolated and it was purified to an electrophoretically pure state from the extract. It was found that the electron micrographic features of the granules after treatment with the enzymes were quite different. A synergistic effect of Amyl III and GA I was observed for the digestion of raw starch granules.
Laboratory of Enzyme Chemistry, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan. matutaka@ri.ncvc.go.jp
Takayoshi
T
Matsubara
Youssef
Y
Ben Ammar
Trisanti
T
Anindyawati
Satoru
S
Yamamoto
Kazuo
K
Ito
Masaru
M
Iizuka
Noshi
N
Minamiura
D001230:Aspergillus / Q000201:enzymology*; D003594:Cytoplasmic Granules / Q000737:chemistry* / Q000648:ultrastructure; D005087:Glucan 1,4-alpha-Glucosidase / Q000302:isolation & purification / Q000378:metabolism; D006358:Hot Temperature; D010316:Particle Size; D011198:Solanum tuberosum / Q000737:chemistry; D013213:Starch / Q000378:metabolism*; D003313:Zea mays / Q000737:chemistry; D000516:alpha-Amylases / Q000302:isolation & purification / Q000378:metabolism*
D013213:Starch; D000516:alpha-Amylases; D005087:Glucan 1,4-alpha-Glucosidase