一株高环境适应性纤维素降解菌的筛选及鉴定

Screening and Identification of A Cellulolytic Bacterium with High Adaptability to Environment

从造纸厂废纸浆中分离到一株纤维素降解细菌CP4，在温度为20～50℃和pH为5～10的条件下，CP4能够快速生长并分泌纤维素酶。在35。C和pH为9的条件下，培养8h后CP4开始产酶，培养3d后相对酶活为5．43mm／d。为确定CP4的分类学地位，PCR扩增后测定其16SrDNA基因序列，在GenBank中进行同源性比较，并与一些相关细菌构建系统发育树，结合其形态特征和生理生化特征，初步鉴定为巨大芽孢杆菌（Bacillus megaterium）。该菌环境适应能力高，在纤维素类物质污染的治理中具有潜在的应用前景。

A cellulolytic bacterium strain CP4 was isolated from waste paper pulp of a paper mill in Zhengzhou. It can grow rapidly and produce CMC enzyme on CMC media in conditions of pH 5 --10 and temperature 20-50 ℃. CMC enzyme was produced after 8 h culture at pH 8 and 35℃, and the relative activity reached 5.43 mm/d after 3 d culture. For confirming the classification of CP4, morphological, physiological and biochemical characterization were applied and PCR was carried out to measure the gene sequence of 16S rDNA. The 16S rDNA of CP4 was compared with those in GenBank and the phylogenetic tree was constructed with related bacteria. Based on the a- bove results, the strain CP4 was identified as Bacillus rnegateriurn. Due to high adaptability to en- vironment,CP4 will have a great potential to he applied in controlling the pollution of cellulosic material.