The Dynamic And Diversity Of Cultivable Bacteria During Leaves Process Of Yunnan Yellow Sun-cured Tobacco

The dynamic change and diversity of cultivable bacteria on the leaves surface of Yunnan yellow sun-cured tobacco,named Yunshaiyihao,during the tobacco process was studied using the spread plate method.Through the 16S rRNA gene isolated,sequenced and the phylogenetic tree of bacteria constructed,the advantage bacteria were confirmed.Then,the effects of different fertilizing methods(organic fertilizer,compound fertilizer,mixture of organic fertilizer and compound fertilizer and microbial fertilizer)on leaves bacteria amount were studied during the curing process.The results were showed as fellows:1.The total amount of bacteria increased at first,then deceased,and then slightly increased as a whole during the curing process.There were about ten genera of bacteria,including Bacillus,Pseudomonas,Arthrobacter,Exiguobacterium,and so on.Bacillus spp,were the dominant genus of cultivable bacteria on the surface of tobacco leaves.2.During the tobacco process,the number of bacteria on and in tobacco leaves of Yunshaiyihao increased firstly and decreased overall.There was a relative maximum value of bacteria in tobacco leaves between the 4th and 7th days.3.The bacteria quantity both on the surface of and within the tobacco leaves increased first and then fell during the curing process,with the relative maximum value of the bacteria quantity within the tobacco leaves between the fourth and the seventh day.The influence of the fertilizing methods,tobacco leaf positions and the curing time on the bacteria quantity on the surface of the yellow sun-cured tobacco leaves descended as follows,tobacco leaf positions>curing time>fertilizing methods.There was a significant influence of leaf positions on the bacteria quantity within the tobacco leaves.The influence of the three factors on the bacteria quantity within the tobacco leaves descended as follows,tobacco leaf positions>fertilizing methods>curing time.4.Using the Griess method,three bacteria of denitrification ability(S21?S48?S61)were oobtained.The sun-cured tobacco process experiments and TSNA detection showed that the bacteria couLd reduce the TSNA content.