一株降解纤维素木霉的分离与鉴定.doc

一株降解纤维素木霉的分离与鉴定
      
       
摘要：从湖南科技大学溢香园中一株木棉树腐败的根部分离筛选得到1株产纤维素酶较好的木霉菌株cx004。酶活力实验表明菌株经发酵培养5d，产酶酶活达到最高；活性在pH4-7内稳定；pH值为6时酶活最高，50℃处理1h活性稳定。采用传统的分类学方法和镜检观察，结果表明该菌株与绿木霉(Trichoderma virens)菌到表现特征非常相似。为了进一步确定cx004的分类学地位，测定了其ITS序列，分析了相关木霉相应序列的同源性，构建了分子系统发育树，结果表明菌株cx004与绿木霉菌(Trichoderma virens)的亲缘关系最近。综合上述结果，菌株cx004可鉴定为绿木霉菌（T. virens ）

关键词：纤维素酶；绿木霉菌；ITS序列；酶活性

Isolation and identification of a cellulose-degrading strain of Trichoderma
     
Technology　　
Abstract: ＡTrichoderma strain cx004 showing efficient cellulose-biodegrading ability was isolated and purified from a rotten Ceiba in Yixiangyuan park of Hunan University of Science and Technology（HNUST）. The metabolites showed strong cellulase activity after cultured for 5 days.This activity remained stable at 50°C from pH 4 to 7. The cellulase ability reached the highest at pH 6. The results of traditional taxology methods and microscope observation showed that the strain is very similar to Trichoderma virens in most of the phenotypes in tradional physiological and biochemical aspects, as well as in molucular phylogenetic dendrogram built from relatively ITS gene sequences, with which the related strains were compared. Therefore, strain cx004 was identificed as Trichoderma virens.
Key words:  cellulase; Trichoderma virens; ITS sequence; enzyme activity.