Fermentation Of Aspergillus Niger Xylanase, Nature And Applied Research

The influence of conditions(pH, temperature, carbon sources and others) on the synthesis of xylanases production of Aspergillus Niger sb-02 with solid state fermentation and liquid fermentation were studied. When the growth of sb-02 in shake flasks at 28 C for 96hours with initial pH6.0 and 2% bran on hemicellulose substrates it showed high activity of xylanase. The optimal pH and temperature for the crude enzyme filtrate activity of sb-02 are pH4.8, 45-55 C. It is clear from these data that solid fermentation was able to increase the xylanase activity compared with liquid fermentation. So we can make a conclusion that solid state fermentation is prior to liquid fermentation.The xylanase belongs to the hydrolytic enzymes that can decompose the xylan to form xylan dietary fibre and oligo-saccharide. Two Xylanases of Aspergillus Niger sb-02 X I , X II were purified by centrifugation, ultrafiltration ,gel Sephadex G-75 and preparation Gel electrophoresis. The range of optimal temperature and optimal pH of X I , XII for hydrolysis of xylan were 45-55 'C and pH 4.8-5.5 respectively. Data from the SDS-Gel electrophoresis indicated the molecular weight of X I , XII are 22,000 and 40,000 respectively. The CD spectrum showed that the -pleated sheet structure of Xylanases X I , X II were the main conformation with Xylanases activities.After the corn cortex powder was treated with 1%NaOH solution ,it is decomposed by xylanase and cellulase under different conditions. The enzymic product were analyzed by using sepharose Gel 6B. the results of this polymerization showed that the depolymerization of xylan followed a random mechanism and the degree of the depolymerization increased as enzymic reaction time is prolonged. It could be concluded that this enzymic process was suitable for the production of soluble dietary fibre and xylooligosaccharides...