A Nicotine Degradation Isolation And Biological Characteristics Of The Bacteria

Nicotine is a principal alkaloid and toxic composition in breeds of tobacco. Some microorganisms are capable of degradating nicotine in different pathways.In the paper a bacterial strain B5 which was able to utilize nicotine as its sole carbon and nitrogen was isolated from the tobacco leaves from Henan province.For strain B5 degrading nicotine,the temperature and pH range is 4℃～37℃, pH5～pH9.The optimal temperature and pH range is 25℃—30℃,pH6～pH7.By the experimental results of the morphological, physiological and structural characteristics of strain B5 and by the comparison of its 16S rDNA analysis, the strain B5 was identified as Agrobacterium tumefaciens B5.The strain B5 can tolerate high concentration of nicotine up to 4000mg/L.Its can grow in concentration of nicotine from 500mg/L～4000mg/L. In this paper the concentration of nicotine used is 2000mg/L.30h after the inoculation of B5 into nicotine liquid culture medium at 30℃, 200r /min in shaker, the eviolet characteristic absorb of nicotine disappeared at 259nm,and form the new absorb at 231nm and 292nm.The result show the new substances are formed.4 weeks after the inoculation of strain B5 on LB culture medium in the condition of constant temperature at 37℃,the bacteria strain can't grow on the nicotine culture medium again.The result show that the high temperatuere disabled the strain B5 to utilize nicotine and the gene which qulificate the strain B5 to degrade nicotine maybe on the big plasmid.