Characterisation of a thermostable xylanase from Chaetomium sp. and its application in Chinese steamed bread

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• 作者：Zhengqiang Jiang ; Qianqian Cong ; Qiaojuan Yan ; Narasimha Kumar ; Xuedan Du
• 关键词：Characterisation ; Chaetomium ; Chinese steamed bread ; Purification ; Thermostable ; Xylanase
• 刊名：Food Chemistry
• 出版年：2010
• 出版时间：15 May 2010
• 年：2010
• 卷：120
• 期：2
• 页码：457-462
• 全文大小：320 K

文摘

A novel thermophilic xylanase-producing fungus, Chaetomium sp. CQ31 produced 131 U ml⁻¹ of xylanase when grown on a medium containing corncob (3.5 % , w/v) at 37 °C for 6 days. A low molecular xylanase was purified 6.5-fold to homogeneity with a recovery yield of 17.5 % . Its molecular mass was estimated to be 25.1 kDa by SDS–PAGE. The xylanase had an optimum pH of 7.5, and its optimal temperature was 65 °C. Apparent K_m values of the xylanase for birchwood, beechwood and oat-spelt xylan were 1.3, 0.86 and 4.4 mg/ml, respectively. The influence of this xylanase on the quality of Chinese steamed bread (CSB) was further studied. Addition of xylanase in the range 2.5–5.0 ppm caused a 20–24.5 % increase in specific volume over the control and remarkable decrease (8.9–24.2 % ) in firmness was also noticed. This is the first report on the purification, characterisation and application of a xylanase from Chaetomium sp. CQ31.