Bacillus细菌的分离及其芽孢漆酶对染料脱色的影响

Isolation of strain Bacillus and the effects of its spore laccase on dye decoloration and degradation

利用含铜离子的富集培养基,从东北林业大学实验林场蒙古栎林下的土壤中筛选出具有较高漆酶活性的1株细菌,采用形态学、生理生化反应以及16S r DNA序列同源性分析等方法,鉴定其为芽孢杆菌属细菌,命名为Bacillus sp.5`MS。以丁香醛连氮为底物,以芽孢干重计算,其芽孢漆酶的活性高达56.73 U/g。菌株5`MS芽孢漆酶的最适pH值为6.6,最适反应温度为70℃。在100℃条件下,该芽孢漆酶反应活性仍可达最适条件下的34.61%。当染料脱色体系中添加介体乙酰丁香酮时,菌株5`MS芽孢漆酶1 h内对活性黑、靛红及结晶紫的脱色率均达92%以上,4 h内对活性蓝的脱色率达82.8%。

Enrichment medium added with copper ions was used to screen and isolate bacteria with laccase activity from soil at Quercus mongolica forest in northeast forestry university. The strain was identified as Bacillus sp. 5MS judged from morphological, physiological and biochemical characteristics as well as from 16 S rDNA sequence analysis. Its spore laccase activity was 56.73 U/g calculated by dry weight in syringaldazine as substrate. The optimum p H for its activity was 6.6 and the optimum reaction temperature was 70 ℃. Even though the temperature was enhanced to 100 ℃, the spore laccase activity of strain 5MS could remain 34.61% of that in the optimal condition. The spore laccase could decolorize more than 92% of reactive black 5（RB5）, indigo carmine（IC） and crystal violet（CV） in 1 hour,and 82.8% of reactive brilliant blue R in 4 hours at the condition of acetosyringone as the mediator.