| The functional oligosaccharides have become a kind of important functional foods' base materials in recent years.Since they have some specific physiological functions ,such as promoting the multiplication of Bifidobacteria in intestines, keeping a good healthy for peoples, the functional oligosaccharides have been attached important to by the researchers all over the world. A xylooligosaccharide is composed of 2-7 xylose. The link between the molecules isβ-1,4 xylosidate band. It can be prepared byβ-xylanase reaction with cotton seed hull, corn cob or rapeseed hull. It's very difficult for xylooligosaccharide's digestion in intestines. The intestinal survivors of xylooligosaccharides are too much, and can keep a good multiplication for Bifidobacteria. The utilization of the xylooligosaecharide is the highest among the other oligosaccharides. The average yield of the cotton seed hull is very big in China. Most of the cotton seed hull are burnt, although a few are used.It's very important to do the theoretic researches and the processing technologies about the xylooligosaccharide preparation with cotton seed hull.The xylan from agricultural residues cotton seed hull was enzymatic hydrolyzes into crude xylooligosaccharides with xylanases by Sphingomonas paucimobilis and purified preliminarily xylooligosaccharides through the active carbon.With the HPLC repeat detection,The gossypol content of the Cotton Seed Hull was 0.0163%, in line with provisions of the United Nations Advisory Committee (the gossypol content in Cotton Seed Hull should be less than 0.06%),Cotton Seed Hull can be used as food processing materials. the advantage of Cooking method and alkali extraction were consolidated,the optimum pretreatment process conditions of xylan were as follows: the quantity of water was 15 mL·g-1,115℃f or 45 minutes,After pretreatment, the optimum extract process conditions of xylan were as follows: the ratio of water and cotton seeds hull was 20, and the concentration of NaOH was 8%, 110℃for 1 h.The yield of crude xylan was 62.8%.Xylanase producing strains were isolated from special environment NANSHANFOREST and deadwood,XINJIANG etc. Isolates of strains were obtained and assayed for the xylanase activity with a method of transparent zones.10 strains presented the highest activity were selected for further investigation in detail.According to the morphological and physiological characteristics and the result of TLC test,NS5 was identified as Sphingomonas paucimobilis; Research aboutβ-xylanase production showed that the other carbons catabolite repression existed during the producing of target enzyme,xylan was the best carbon source as well as the elicitor. The media contained the surfactant (Tween80 0.08%)was added,which could improve the ability of enzyme production markedly. Under the condition of inoculation concentration 10% and initial pH 8.0 of the medium and 31℃of the culture temperature,the optimal culture time was 96 hours and the maximum enzyme activity of 36.2 U·mL-1 was obtained at 190 rpm.The optimum conditions were at 30℃with the enzyme concentration 15%, the reactive time was 8 hours, the concentration of substrate was 40 g·L-1,the above reaction conditions for enzymatic hydrolysis yield was 53.2%. The optimum conditions of activated carbon decolorization were as follows: the amount of activated carbon 2 g·L-1, decolorizing temperature at 50℃, decolorizing time 50 min,The HPLC showed that 48.56% of the refined oliosaccharides are xylobiose and xylotriose, and 82% are xylooligosaccharides.In this paper, the results of research to improve the use of cotton husk opened up a new way to address both the agricultural and forestry waste. It has also solved the problem of environmental pollution, there is good economic and social benefits.
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