白蚁肠道木质素及纤维素分解菌的分离鉴定及产酶条件优化

Isolation,Identification and Enzyme-producing Conditions Optimization of Lignin-Utilizing and Cellulose-Utilizing Bacterium from the Gut of Termite

利用刚果红法、Azure-B平板法从白蚁肠道中分离出5株同时具有木质素降解和纤维素分解功能的菌株,选取其中分解功能最强的菌株MX5经形态观察、生化鉴定和16S rRNA鉴定为芽孢杆菌属的地衣芽孢杆菌Bacillus licheniformis。产酶条件优化试验结果表明,菌株MX5以w=0.5%秸秆为碳源,w=0.5%酵母粉和硫酸铵混合物为氮源,初始pH8.0,37℃摇瓶培养96 h,接种量为1%时,产酶活性最高。筛选出产酶活性优良的菌株,对提高木质纤维素的利用率、降低环境污染等方面意义深远。

Five strains of bacteria with decomposed function for lignin and cellulose were isolated from gut of termite with a congo red and Azure-B plate method. MX5 strain with the strongest decomposed function was identified as Bacillus licheniformis by morphological observation, physiological and biochem-ical identification and 16S rRNA identification. Optimization test of producing lignin and cellulose show MX5 strain has the highest production activity with O. 5% of straw as carbon source, mixture of 0.5% yeast extract and ammonium sulfate as the nitrogen source and cultrue in shake flask at 37 ℃ for 96 h with 1% noeulation amount and initial pH 8. 0. Selecting excellent strains which produced ligninase and cellulase has far-reaching significance for improving the utilization of wood fiber feed, reducing environ- mental pollution and so on..