UULlZA TION OF SOME AGRICULTURAL BY-PRODUCTS FOR IMPROVING THE BIOSYNTHESIS OF Aspergillus ten'eus THERMOSTABLE AMYLOGLUCOSIDASE AND a· AMYLASE AND ITS USES FOR STARCH DIGESTION | ||||
| Journal of Agricultural Chemistry and Biotechnology | ||||
| Article 2, Volume 27, Issue 7, July 2002, Page 4935-4952 PDF (1.75 MB) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jacb.2002.255927 | ||||
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| Authors | ||||
| T. S. M. Shady,1; A. A. Nasr1; Nadia A. A. Ali1; Afaf-Hanem M. Ramadan2 | ||||
| 1Mlcroblol. Dept.; Solf, Water and Environ. Res. Institute, Agrlc. Res. Center, Giza, Egypt. | ||||
| 2Home Economics Dept., Fac. of Specific Education, Mansoura Unlv., Mansoura, Egypt. | ||||
| Abstract | ||||
| The biosynthesis of Aspergillus terreus thermostable amyloglucosidase and a-amylase were improved greatly in this study, which the results revealed that: Ingredients of the medium No. (1) used in this study gave highest enzymes productivity. Three and two days incubation improved its biosynthesis, respectively. Maltose, glucose syrup (3%), zea glutein (0.28% as nitrogen content) supported highest enzymes productivity. 2.5% (v/v) inoculum size to volume of the fermentation media, 35°C, pH 5.0 and 225 rpm as agitation rate and 1 :6.25 (vlv, vol of mediumlvol of the "ask) as aeration rate also supported highest enzymes production. PH 5.0 and 5.0 to 8.0 were found as the optimum pH for glucoamylase and a-amylase, respectively. Both enzymes were highest stable in the pH range between 4.0 to B.O. 60cC and 70°C were found as the temperature optima for both enzymes, respectively. Both enzymes were highest stable up to BO°C, indicating that, these enzymes are thermostable enzymes. K+, Na+, Mg+2 and Ca+2 strongly induced glucoamylase activity, but Fe+2 was found as slight activators of a-amylase. Hg·2 and Zn+2 inhibited both enzymes activily. Starch was found as the best substrate of these enzymes which showed highly affinity with those enzymes. Different starch substances were highly hydrolyzed with a mixture of A. taTreus glucoamylase and a-amylase, which maximum hydrolysis was attained after 5 hours of hydrolysis. This is may be due to its thermostable character and its highly affinity between enzymes and substrate. Therefore, these enzymes were highest successful in similar biotechnological process. | ||||
| Keywords | ||||
| Aspergillus terre us; amyloglucosidase; a-amylase; thermostable; biosynthesis; submerged fermentation; starch digestion | ||||
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