32 nicotine-degrading bacterial strains were separated and screened from tobacco and soil with selectivity culture medium, in which nicotine was the sole source of carbon and nitrogen. Among them, strain A3 was the best one with strong ability to degrade nicotine, and it could secrete protease and amylase simultaneously. This strain was inoculated in the medium with 0.1% nicotine as carbon and nitrogen source, and incubated at 30℃ for 18 h with reciprocal shaking (200 r/min) ,the ratio of nicotine degradation was 96. 3% ; and the ratio of degradation was 36.1% when the strain was inoculated in 0.2% nicotine for 48 h, meanwhile, the activities of protease and amylase were 42.6 U/mL and 16.5 U/mL respectively. According to the normal morphology, physiological, biochemical characteristics and 16S rDNA gene sequence, the strain A3 was identified as Arthrobacter rdcotianae GYC103.%以烟碱为唯一碳源和氮源,从烟叶及植烟土壤中分离筛选出32株能够不同程度降解烟碱的菌株,复筛后发现一株具有强烟碱降解能力同时能够产生蛋白酶和淀粉酶的菌株A3,该菌株在含0.1％烟碱为唯一碳氮源的培养基中,,烟碱降解率为96.3％,在以0.2％的烟碱为唯一碳源和氮源的培养基中,30℃下摇床培养(转速为200 r/min)48 h,烟碱降解率为31.6％,同时蛋白酶和淀粉酶酶活分别达到42.6 U/mL和16.5 U/mL.对菌株A3进行常规形态学观察、生理生化特征研究、16S rDNA基因序列分析,将该菌株初步鉴定为烟草节杆菌,命名为Arthrobacter nicotianae GYC103.
展开▼
