一株瘤胃纤维素解菌的分离鉴定及其.docVIP

一株瘤胃纤维素降解菌的分离鉴定及其纤维素降解特性 刘占英1,2 侯先志1* 刘玉承1 刘小刚1 胡建华2 杨 帆1 赵子夫1 (1. 内蒙古农业大学动物科学与医学学院 内蒙古 呼和浩特 010018)(2. 内蒙古工业大学化工学院 内蒙古 呼和浩特 010051) 摘 要: 从蒙古绵羊瘤胃内容物中分离到一株纤维素降解细菌WH-1, 通过形态、生理生化特征、G+C mol%含量和16S rRNA序列分析对分离菌株进行鉴定, 鉴定为溶纤维丁酸弧菌属(Butyrivibrio fibrisolvens)的溶纤维丁酸弧菌(Butyrivibrio fibrisolvens)。同时, 用Mega 4.1软件构建的系统发育树显示分离菌株WH-1与多株溶纤维丁酸弧菌(Butyrivibrio fibrisolvens)的亲缘关系最近。对该菌株纤维素降解特性的初步研究表明：当温度为37(C、pH值为7.0、接种量为25%、纤维二糖添加质量占总碳源质量的20%时, WH-1的72 h滤纸降解率达到16.81%±2.99%。Isolation, Identification and Characterization of a Cellulose-degrading Bacterial Strain from the Rumen of Sheep LIU Zhan-Ying1,2 HOU Xian-Zhi1* LIU Yu-Cheng1 LIU Xiao-Gang1 HU Jian-Hua2 YANG Fan1 ZHAO Zi-Fu1 (1. College of Animal Science and Animal Medicine, Inner Mongolia University of Agriculture, Hohhot, Inner Mongolia 010018, China)(2. College of Chemical Engineering, Inner Mongolia University of Technology, Hohhot, Inner Mongolia 010051, China) Abstract: A bacterial strain named as WH-1 that can degrade cellulose was isolated from the rumen of the Mongolia sheep. The isolate was identified as Butyrivibrio fibrisolvens based on phenotypic and morphologic properties, the G+C mol% content of DNA and the 16S rRNA gene sequence analyses. In addition, the phylogenetic analysis of the 16S rRNA sequence also indicated that the isolate grouped closely with other members of Butyrivibrio fibrisolvens. The primary factors affecting the degradative ratio of cellulose were examined. The highest degradative ratio of filter paper reached 16.81%±2.99% under the conditions of 37(C, pH 7.0, inoculum size being 25%, and the percentage of cellobiose in total carbon sources being 20% within 72 hours of fermentation. Keywords: Cellulose-degrading rumen bacterium, Butyrivibrio fibrisolvens 纤维素是地球上最丰富、数量最大的可再生有机资源[1], 占植物干重的1/3到1/2[2], 在碳循环中扮演着关键性角色[3]。然而, 由于纤维素不溶于水和有机溶剂的难降解特性, 使如此庞大的可再生资源没有得到很好地利用。目前, 在我国, 纤维素类资源大部分被烧掉, 既破坏生态平衡, 又污染环境, 且能量利用率低(10%左右)[4], 还有一些纤维类资源由于未及时处理而变成固体垃圾, 造成严重的环境污染。所以, 如果用适当的方法将这些可再