OPTIMIZATION OF FERMENTATION MEDIUM FOR α-AMYLASE PRODUCTION BY FREE AND IMMOBILIZED Aspergillus niger ON PALM TREE FIBERS

Autor: Reda M. Abou Al-Alla, W. A. Bazaraa, Nagwa M. El-Shimi
Rok vydání: 2007
Předmět:
Zdroj: Journal of Agricultural Chemistry and Biotechnology. 32:6753-6768
ISSN: 2090-3707
DOI: 10.21608/jacb.2007.201362
Popis: Various strains of Aspergillus niger were screened for α- amylase synthesis. Strain 3 proved to be the highest producer (1.82 U. ml-1). Production of α- amylase by Aspergillus niger 3 in batch shaking system was optimized. The highest α- amylase production (5.63 U. ml-1) at 30 oC was achieved when Aspergillus niger 3 was allowed to grow aerobically in a buffered medium (pH 7.0) containing 2 % dextrin and 1.6 % tryptone. The enzyme was found to be highly inducible by dextrin, while the presence of glucose or fructose repressed its synthesis. Palm tree fiber (PTF) was evaluated for the first time as a novel fungal cells supporting material. Conidiospores were firmly attached onto the rough surfaces of the PTF as proved by SEM photomicrographs. The immobilized preparations were used in batch system for α- amylase production with maximum sp. activity of 0.49 U. ml-1.mg-1. Such sp. activity was improved to 0.8 U. ml-1.mg-1 by modifying fermentation broth to contain 0.5 % dextrin and 2.4 % tryptone.
Databáze: OpenAIRE