Study On The Relation Between Microbial Community Structure And The Quality In Cigarette Processing And Storage Process

In recent years, the quality and security of cigarette materials increasingly become the focus of industrial and public attention. Some studies have showed that the surface of flue-cured tobacco leaves had diverse of microbial resources, the existence of microorganism plays an important role in the quality of tobacco leaves. However, the community structure and the relation with the quality of tobacco leaves in the differnent cigarette primary processing and cigarette products have not been reported; In addition, the existing research lack comprehensive, systematic and in-depth understanding of microbial ecological system on flue-cured tobacco leaves due to the limitation of method and technology.In this study, firstly, we launched high-throughput sequencing technologies and QIIME pipeline to study the community structure, dominant groups composition and dominant taxa viariation of bacteria and fungi on flue-cured tobacco leaves from different cigarette primary processing and different store styles in cigarette products of R and Z brand. In the analysis of the bacterial group, thin-plate primary processing of R brand cigarette had twelve phyla, the dominant group includes Firmicutes, Proteobacteria, Actinobacteria and Cyanobacteria; air-flow primary processing had twenty-one phyla, the dominant group includes Proteobacteria, Cyanobacteria, Firmicutes, Actinobacteria and Bacteroidetes. Thin-plate primary processing of Z brand cigarette had eighteen phyla, the dominant group includes Proteobacteria, Cyanobacteria, Firmicutes and Actinobacteria; air-flow primary processing had thirteen phyla, the compositions of dominant group were the same with thin-plate primary processing. R brand cigarette product stored by different styles had twenty phyla, the dominant group included Firmicutes, Cyanobacteria, Proteobacteria, Bacteroidetes and Actinobacteria. Z brand cigarette product had seventeen phyla, the dominant group included Cyanobacteria, Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes. In the analysis of fungal group, thin-plate primary processing of R brand cigarette had twelve phyla, the dominant group included Ascomycota, Basidiomycota and unclassified fungi; air-flow primary processing had three phyla, the compositions of dominant group were the same with thin-plate primary processing, thin-plate primary processing of Z brand cigarette had six phyla, the dominant group included Ascomycota, Chytridiomycota, Basidiomycota and unclassified fungi; qiliu primary processing had five phyla, the compositiond of dominant group were the same with thin-plate processing line. R and Z brand cigarette products both had six phyla with the same taxon, the compositions of dominant group were the same as well, including Ascomycota, Basidiomycota, Chytridiomycota and unclassified fungi. Bacteria and fungi resources were abundant, which had great potential for exploration. The variation of dominant bacteria and fungi in all primary processing of two kinds of cigarette showed the same pattern:along with the machining process, the amount and number of dominat taxa were changing constantly in the same primary processing, the primary processing had a huge influence on dominant taxa; the variation of dominant bacteria and fungi on the surface of two kinds of cigarette products stored by all styles also showed the same pattern:with the increasingly extended store time, the dominant taxa were changing all the time, the difference was bigger and bigger compared with the control.Secondly, using the method of continuous flow to test the conventional chemical indicators (total sugar, plant alkaloid, nitrogen, chlorine and potassium) content of representative tobacco leaves, the distribution of dominant taxa and variation of conventional chemical indicators are the main research objects to explore the change of the tobacco leaves quality and the relationship between the change of dominant bacteria and fungi through statistical analysis, then get the kinds of dominant taxa which are closely linked with the change of tobacco leaves quality. Based on conventional chemical indicators of tobacco leaves in the beginning and the end of different cigarette primary processing (8samples) and those of cigarette products stored in four cities for one month and the control (10samples), principal component analysis shows that the difference on conventional chemical indicators of tobacco leaves before and after the primary processing and storement are obvious. Redundancy analysis shows that the changes of dominant bacteria and fungi on tobacco leaves before and after primary processing play important roles in the quality of tobacco leaves, and the overall impact degree of dominant fungus change is higher than bacteria, Firmicutes, Chytridiomycota and Basidiomycota are very important to the quality of tobacco leaves; the dominant bacteria and fungi in cigarette products before and after storing at different cities play the key role in the formation of the tobacco leaves quality, but the relation between the dominant fungi and tobacco leaves quality are not close, Proteobacteria, Actinobacteria, Firmicutes, Bacteroidetes and Chytridiomycota are crucial to the quality of tobacco leaves.Through this study, we fully understand the relation between microbial community structure and the tobacco leaves quality in cigarette processing and storage process, then provide the scientific basis and theoretical guidance to the development of microbial resources and artificial regulation of tobacco leaves quality.