Study On The Water Soluble Sugar Analysis And Xylase Fermentation Characteristics Of Corn Straw Treated With Steam Explosion

Steam explosion could change the composition of corn straw. These changes may be make corn straw resources get more extensive application. In this paper, Composition of corn straw treated with low-pressure steam blasting are analyzed, at the same time, comparing with xylanase making corn straw, watered corn straw, corn straw treated with steam explosion as substrate. And optimization of conditions of straw as substrates for the of Aspergillus niger solid fermentation for producing xylanase were studied. The results are as follows:1. Study on the composition of corn straw treated by low pressure steam explosion. The straw after bursting contains more soluble sugar, accounting for11.27%of the total weight of straw; soluble sugar in the untreated corn straw only accounted for0.9%. The results of determination of molecular weight showed that, the molecular of soluble sugar from corn stalk treated with steam explosion is between1000and200000. The polysaccharide which the molecular weight more than10000of water soluble sugar is more than68%. Contrasting with soluble sugar in corn stalk shows that the distribution range of souble sugar from steam exploded straw is wider. The soluble sugar of monosaccharide composition and molecular weight were measured and analyzed by High performance liquid chromatography. The analysis results show:the soluble sugar of corn stalk treated by steam exploded is composite of arabinose, xylose, galactose, glucose, mannose, rhamnose, and glucose and xylose accounted for the most, the xylose accounted for34.121%; Among the soluble sugar of untreated corn straw, xylose accounted for only9.995%. The proportion of cellulose and xylan is higher in soluble sugar.2. Characteristics of steam exploded corn stalk solid fermentation of Aspergillus niger xylanase were studied. The results showed that, compared with corn straw, enzyme production increased28.28%with the steam exploded corn straw as substrates, single factor and orthogonal experiment analysis showed the results of optimization are as follows:the best nitrogen source is (NH4)SO4; the optimal particle size is0.5cm; the optimum culture time was96h, the optimum ratio of solid to liquid1:4(W/V), the optimal temperature25℃, the optimal initial pH5.5, the optimal inoculation quantity is1mL (106/mL); the optimal ratio of bran and straw is1:4. Xylanase fermentation with the best optimized fermentation conditions, the enzyme activity can reach to3526.772IU/g, which is3.28times of enzyme activity before optimization.