Isolation And Identification Of Microorganisms In Aged Tobacco Leaves And Their Application In Tobacco Leaf Fermentation

The purpose of this study was to screen the sweetening microorganisms in tobacco leaves and explore the sweetening mechanism of microorganisms on tobacco leaves.By collecting the same storage environment down from Hunan,Jiangxi,Sichuan,Guangdong and other regions of the tobacco leaf samples,the leaf tobacco microorganism separation and identification based on the degradation of macromolecular substances ability,screening strains of tobacco fermentation,by expert evaluate sensory smoking after fermentation effects,determination of flavouring obviously strains fermented tobacco chemical composition and main content of aroma components,analysis its flavoured mechanism,basically have the following results:1.A total of 647 strains of microorganisms were screened from flue-cured tobacco leaves,including 356 strains of Bacteria,278 strains of Fungus and 13 strains of Actinomycete.Among them,208 strains were isolated from tobacco leaves from Fuzhou,Jiangxi province.The microbial strains were mainly distributed in the middle tobacco leaves,accounting for 46.52% and less in the upper part.Among different grades of tobacco leaves,the number of microorganisms in the superior tobacco leaves was higher than that in the inferior tobacco leaves.The shorter the aging time was,the more microorganisms were isolated.2.The strains with multiple degradation abilities were applied to the rapid fermentation of tobacco leaves,and five strains were obtained,in which the quality evaluation of 311 and 318 strains on tobacco leaves was increased by more than 4%.The 16 S r DNA of flavoring microorganism was extracted for sequencing,and combined with physiological and biochemical tests,the bacterial strains 176,311,117 and 123 of tobacco flavoring microorganism were identified as Bacillus and the bacterial strain 318 as Pseudomonas.Strain 176 has the ability to degrade protein and starch.Strain 311 had the ability to degrade protein and starch.Strain 318 has the ability to degrade protein,starch and pectin.Strain 117 has the ability to degrade protein,starch and cellulose.Strain 123 has the ability to degrade protein,starch,pectin and cellulose.3.The content of main chemical substances in the fermented tobacco leaves by the flavoring strain were detected.The total sugar content of treated tobacco decreased and the reducing sugar content increased after fermentation by the sweetening strain.The total nitrogen content of tobacco leaf samples treated by strains176,123 and 117 decreased,and the total nitrogen content of tobacco leaves treated by strains 311 and 318 increased,while the nicotine content of tobacco leaves treated by strain 117 increased.Meanwhile,the potassium content and chloride content of tobacco leaves were reduced by strain 117.4.The contents of aroma substances in tobacco treated by 311 and 318 strains were determined by gc combined with GC.Compared with the control samples,the contents of nitrogen,ketones and alcohols in the treated tobacco increased,while the contents of acids,esters and phenols decreased.To analyze the content of degradation products of various aroma preconditions in tobacco leaves,the degradation products of carotenoids,cebutane,phenylalanine,alkaloids and Maillard reactants were all increased in the tobacco leaves fermented by strain 318.The content of reactants and alkaloids in strain 311 was lower than that in control tobacco.