Preparation Of Xylooligosacchatide From Wheat Bran By Biological Technique

The study focuses on producing xylooligosacchatide taking wheat bran as raw material by biological technique. First separating starch and protein by enzymic hydrolysis to get a kind of substance which content a lot of xylan. A stain is gained that product xylanase whose activity is high by mutagenesis and selection, and investigating the condition of liquid state fermentation and characteristics of produced xylanase. Xylooligosacchatide is produced by directional degrading xylan by xylanase which is synthesized by Aspergillus niger, and investigating purifying of Xylooligosacchatide solution and preteatment of bottom thing.Besides cellulose and hemicellulose, the wheat bran contents a lot of starch and protein and phytic acid and antioxidant, so making full use of wheat bran is very important. First the composition of wheat bran is analysized. We conclude that the content of holocelluloses is 46.05% and the content of celluloses is 2.35% and the content of pentosans is l9.42%, which shows that the wheat brans from Heilongjiang province are in favor of preparation xylooligosacchatide, because they have high quantity of the xylan. While the content of lignocelluloses is 6.01% and the content of fat is 3.45%, which shows that the substrate from wheat brans is easy to be hydrolyzed by xylanase. The content of starch is 18.60% and he content of protein is 17.69%.Hydrolyzed to soluble content by α-Amylase and Alkaline Protease, starch and protein are separated by bath. Taking the remained content of starch of hydrolyzed wheat bran as review target, we investigate the factor effecting hydrolysis by One-way Analysis of Variance to confirm optimal parameters. The remained content of starch is reduced to below 0.5 % from original 18.6 %. To separate protein, Papain Enzymolysis and Extraction by Alkali and Alkaline Protease Enzymolysis are adoped. Taking the remained content of protein of separated wheat bran as review target, we investigate the factor effecting hydrolysis and Extraction by One-way Analysis of Variance and ANOVA to optimize parameters. Finally the beast way of separating protein is Alkaline Protease Enzymolysis. The remained content of protein of separated wheat bran is only 0.62%. The wheat bran that have been discarded starch and protein contents 34.51% pentosans.In the study of mutagenesis and selection of stains and fermentation for xylanase synthesis, we take Aspergillus niger as original fungus to gain a stain that could product xylanase whose activity is highest. It was treated by fluka and ultraviolet. Then we take Bacillus cereus and Bacillus subtilis as original fungus to gain a stain that could product xylanase whose activity is highest. It was treated by only ultraviolet. Through comparison we chosed one that could product xylanase whose activity is highest as examinational fungus, and investigated thecondition of liquid state fermentation to synthesis xylanase. Taking xylanase activity by DNS as review target, we investigate the factor effecting synthesis by One-way Analysis of Variance and ANOVA to optimize parameters. Xylanase activity was increased to 58.3050 U/ml from original 17.3716 U/ml.In the study of purification and characteristics of xylanase, we take (NHOSO4 as precipitator, and analyses xylanase activity after and before purification and its hydrolyzing xylooligosacchatide solution by HLPC. The xylanase activity was slightly improved after refined. The hydrolyzed sugar solution hydrolyzed by unpurified one contents 61.39% xylooligosacchatide, while the sugar solution hydrolyzed by purified one contents 81.15%. After that characteristics and Km and Vmax were analyzed. The optimal temperature is 50°C and the optimal pH is 4.2 and Km is 1.69mg/ml and Vmax is 22.36mol/min.In the study of production and purification of xylooligosoccharides, factors effecting production of xylo-oligosoccharides from wheat bran xylan hydrolyzed by xylanase was analyzed by One-way Analysis of Variance and general traversing analysis of regression to decide optimal parameters. The highest concentration of whole sugar is 3.6g/L. After purified by Polyamide Column Chromatography, xylooligosoccharides contents 70.00% xylobiose analyzed by HLPC. To evaluating the gain ratio, we adopted three pretreated method to deal with wheat bran xylan that are ultrasonic and microwave and acid. The ultrasonic pretreatment is best method. The gain ratio of xylooligosacchatide is 15.21%.Obtained hydrolyzed sugar solution contents 67.70% xylobiose and 4.74% xylotr and 82.44% xylo-oligosoccharides.Observing original and getted rid of starch and protein and hydrolyzed by xylanase wheat bran by scan electron microscope. The original wheat brans covered with a lot of rounded substance. We guess it is maybe dissociated starch granule. The wheat brans get rid of starch and protein have obvious changes. They have ridgelike lines formatted by tightness arranged hollow tubes. Beside them they also are alveolate. The hydrolyzed residues there are two states too. The alveolate ones whose wall are more flimsy and the ridgelike ones whose bran have some craze showing us that xylanase dose some function to wheat bran.