降解烤烟秸秆和烟碱菌株的筛选及其产酶特性

Isolation of microorganisms producing enzyme capable of degrading tobacco straw and nicotine

摘要:

摘要:【目的】为获得能够降解烤烟秸秆和烟碱的菌株，并探索其降解烤烟秸秆的利用途径。【方法】以烤烟秸秆为唯一碳氮源，从烟田土壤中进行了菌株的筛选。采用形态学观察、生理生化特性鉴定、16S rRNA基因序列鉴定等方法对该菌株进行了鉴定，并对其以烤烟秸秆为底物进行液态发酵的产酶活性和木质纤维素降解效果进行了测定。【结果】结果表明:该菌株为巨大芽孢杆菌(Bacillus megaterium)。在以烤烟秸秆为主要营养物质液态发酵条件下该菌株具有较强的木质素降解能力，最大漆酶活力达到418.52 U/L，而木质素过氧化物酶和锰过氧化物酶的最大酶活分别为19.71 U/L 和64.71 U/L。此外，发酵20 d后该菌能够完全降解发酵液中的烟碱。【结论】本研究筛选到了1株能够较好降解烤烟秸秆和完全降解烟碱的巨大芽孢杆菌(Bacillus megaterium)，且该菌株具有利用烤烟秸秆生产漆酶的应用价值。

Abstract:

Abstract:［Objective］ The aim of this study was to screen tobacco straw and nicotine degrading microorganism．［Methods］The bacterium was isolated from tobacco field soil using medium containing tobacco straw as the sole carbon and nitrogen source．We identified the bacterium through morphological and physiological characterization combined with the result of 16S rＲNA gene sequence and data analysis．We also studied the lignocelluloses degradation and enzyme activities related to the degradation of lignin and cellulose in liquid state fermentation of tobacco stalk.［Results］The bacterium was identified as Bacillus megaterium and we had demonstrated that it has a good ability to degrade lignin in tobacco straw when fermented in liquid state．It showed the highest laccase production of 418. 52 U/L while the highest lignin peroxides and manganese peroxides activity was 19.71 U/L and 64.71 U/L．On the other hand，we also found that nicotine in tobacco stem was totally degraded 20 d after inoculation.［Conclusion］to the isolated Bacillus megaterium is capable of degrading tobacco straw partially and nicotine totally.