Study On Orientation And Aroma Improving Effect Of Phyllosphere Dominant Microbe Of Flue-Cured Tobacco During Aging Process

This article analyzed dynamic changes of several enzymatic activity and phyllosphere bacterium of three flue-cured tobacco varieties aged for different time by microbiology, enzymatic and molecular biological methods and technologies. The microorganism diversity on surfaces of tobacco leaves was analyzed using PCR-DGGE technology,mutual dominant microbe of three flue-cured tobacco varieties was appraised,and culturable dominant microorganism was also appraised by traditional plate cultural method. We studied effects of enzyme and microbe on content of volatile aroma composition by spraying enzyme and dominant microbe to the surface of tobacco leaves.Results as follow:1. Dynamic changes of several enzymatic activity of flue-cured tobacco leaves aged for different periods.Results showed that polyphenol oxidas activity,peroxidase activity,amylase activity, protease activity changed unanimously.At the beginning of the aging process, enzymatic activity of these four kinds of enzyme tended to increased; Enzymatic activity reach their peak after six or nine months, then decreased gradually. there were no difference between different varieties, which indicated that dynamic changes during aging process had nothing to do with genotype of tobacco leaves.2. Separating and appraising dominant bacterium on the surface of flue-cured tobacco leaves aged for different periods.Dominant bacterium on the surface of flue-cured tobacco leaves aged for different period was separated and appraised by PCR-DGGE technology.Results showed that bacterial diversity existed a big diversification between leaves of the same variety.Numbers of some bacterium increased while some decreased during aging process,but total numbers of bacterium decreased with the aging time; Tobacco leaves of same variety had more same dominant bands in different aging periods; Though bands were quite different, tobacco leaves of different varieties had many common dominant bacterium.DNA sequences of bacterium showed that common dominant bacterium of different varieties and aging periods were: Bacteriovorax sp. EPC3,Bacillus megaterium,Uncultured Sphingomonas sp, Uncultured bacterium, Uncultured...