Degradation of Raw Starch Granules by α-Amylase Purified from Culture of Aspergillus awamori KT-11

Abstract

Raw-starch-digesting α-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.

Recent Advances in Microbial Raw Starch Degrading Enzymes

“…This leads to physical disintegration of structure and consequent exposure of new sites susceptible to either or both enzymes. Most common synergies are completed by endo-and exo-acting RSDE [12,26,36,91]. Synergic action also has been reported for two endo-RSDEs: salivary α-amylase and pullulanase [92].…”

“…This process is energy-intensive, thus Aspergillus awamori -- [8] Aspergillus awamori var. kawachi -- [9][10][11] Aspergillus awamori KT-11 air α [12] Aspergillus carbonarius rotten cassava β [13] Aspergillus cinnamomeus -GA [14] Aspergillus ficum -α [15] Aspergillus niger -GA [16,17] Aspergillus niger Cassava waste - [18] Aspergillus niger AM07 Soil α, GA [19] Aspergillus niger NIAB 280 -GA [20] Aspergillus niger sl. 1 Soil - [21] Aspergillus oryzae -GA [22] Aspergillus sp.…”

Valorization of Residual Agroindustrial Cakes by Fungal Production of Multienzyme Complexes and Their Use in Cold Hydrolysis of Raw Starch

“…In literature, filamentous fungi from the genera Aspergillus and Penicillium are among the most studied producers of rawstarch degrading amylases [17,18], as well as amylases that could act at relatively mild conditions [19]. Furthermore, species from these genera have been also described for their ability to produce accessory hydrolases [20][21][22][23].…”

Novel α-Amylases Amy A1 and Amy A2 from digestive tract of tropical house cricket Gryllodes sigillatus (Orthoptera: Gryllidae): hydrolysis and transglycosylation reactions

“…Indeed, starch enzymatic hydrolysis is characterized by a high reaction rate. Moreover, several studies were reported on the hydrolysis on starches from tropical tubers and roots (Valetudie et al,1993;Adebiyi et al, 2005;Omemu et al, 2005) and cereals (colonna et al, 1988;Matsubara et al, 2004) . In addition to hydrolysis reactions, some α-amylases as many other glycosyl hydrolases also catalyse various types of transglycosylation reactions.…”