Production of thermostable amyloytic enzymes by aspergillus niger F-909 under soild state fermentation

ABSTRACT

The production of three thermostable amylolytic enzymes; namely, alpha-amylase [EC 3.2.1.1], glucoamylase [EC 3.2.1.3] and alpha- glucosidase [EC 3.2.1.20] was obtained by cultivating a new local isolate of Aspergillus niger on radicle the waste of malt beverages manufacture using solid state fermentation technique [SSF]. The enzymes production was markedly affected by the amount of waste in the fermentation vessel; however, the amylases were produced under a wide range of pH values [3.0-7.0]. Inoculum size had a slight effect on the production level. Investigation of the medium constituents showed that radicle can be used individually as complete medium for amylases production without any other supplementation. The enzymes filtrates were employed to hydrolyze 20% slurry of raw potato starch giving 98.2% digestion and 97.6% saccharification after 16 and 22 hours, respectively