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.
60^cC 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.