Utilization of some agricultural by-products for Aspergillus niger M₂ amylase production with soild-stat fermentation and to be used in bread staling evaluation [electronic resource].

Includes references.

Because of the increasing demand on starch-hydrolyzing enzymes, this study was focused on studying factors controlling the production of α-amylase, β¬ amylase and glucoamylase from Aspergillus niger M₂ and also to study the effect of these enzyme on quality of balady bread and its staling properties. Spent brewing grain (SBG), was used as a solid substrate for the production of these enzymes. Different agro-industrial by-products were tested for the production of α, β and glucoamylase. Maximum amylases yields, α, β and glucoamylase synthesis by A. niger M₂ strain were 770, 390 and 950 IU/g dry substrate (g/ds), respectively. These values were obtained on the optimized media after 96 hrs and suitable conditions of initial moisture, inoculum size, initial pH and incubation temperature of 65%, 10⁶ spores/gds, 5.0 and 30 °C, respectively. Maltose induced the enzymes biosynthesis and glucose syrup supported the enzymes formation. Amylases production was stimulated at 3.0% of glucose syrup. Corn steep liquor (CSL) at 0.21% as N gave highest amount of these enzymes.

Summary in Arabic.

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