【摘要】 【目的】分离获取产纤维素酶高效菌株,并对其进行系统分类鉴定。【方法】以羧甲基纤维钠为唯一碳源,从烟草秸秆自然发酵腐熟物中选择性分离了51株产纤维素酶细菌及放线菌。通过刚果红染色初筛筛选到产纤维素酶活力较高的9株菌,根据菌株的16S rRNA基因序列确定了这些菌的系统发育地位。【结果】基于纤维素酶活力测定的复筛选定了高效菌株Luteibacter sp. L43。单因素试验确定了pH、碳源浓度、氮源浓度对L43发酵液中滤纸酶活、外切酶酶活、内切酶酶活的影响,并优化了发酵条件,即在pH为6、羧甲基纤维素钠浓度为12.5 g/L、NaNO₃浓度为5 g/L的羧甲基纤维素钠培养基中滤纸酶活达16.9 U/mL,外切酶酶活达39.62 U/mL。【结论】本研究为烟草秸秆腐熟提供了优良产纤维素酶菌株资源,为Luteibacter sp. L43的开发利用奠定了基础。更多还原

【Abstract】 【Objective】The present paper aimed to get high efficient cellase-producing bacteria and determine the taxonomy. 【Method】Sodium carboxymethylcellulose was selected as the sole carbon source to isolate cellulose-producing microorganism. A total of 51 bacteria and actinomyces were isolated from natural fermentation material of tobacco straw. Nine isolates possessed high cellulase activities in congo dye experiment. The phylogenetic relationships of cellulase producing bacteria and actinomyces were determined through the analyses of phylogenetic trees constructed using 16 S rRNA gene sequences. 【Result】 Luteibacter sp. L43 possessed the highest cellulase activities in enzyme activity tests. The effects of the single factor including pH, carbon and nitrogen concentration on filter paper enzyme, endo-β-1, 4-glucanases and exo-β-1, 4-glucanases for L43 were determined. Under the condition of pH6, sodium carboxymethylcellulose concentration 12.5 g/L and NaNO₃ concentration 5 g/L, the highest cellulase activities of endo-β-1, 4-glucanases and exo-β-1, 4-glucanases of L43 were 16.9 and 39.62 U/mL, respectively. 【Conclusion】This study provided a good cellulose producing bacteria for tobacco straw fermentation and laid a foundation for the development and utilization L43.更多还原