The Diversity And Dynamic Of Microorganism On Flue-cured Tobacco Leaves During Different Aged Phases

Microorganisms on flue-cured tobacco leaves can play important roles in the aging process. However, microbial communities in its fermentation process remain largely unknown. Traditional methods including DGGE, RFLP and Clone library might have caused an underestimate of the diversity of microorganisms. In recent years, a new technology developed based on next-generation sequencing allow large-scale analysis of microbial communities. It can detected the microorganisms more comprehensively. There are few reports about microorganisms on flue-cured tobacco leaves by high-throughput sequencing. In this study, firstly we compare Clone library and High-throughput sequencing in detecting microbial communities on flue-cured tobacco leaves. Then we explored the dominant microorganisms and dynamic on flue-cured tobacco leaves during every two month by high-throughput sequencing. The results are as follows:1. Compared with the clone library, high-throughput sequencing can provide more sequences, and the rarefaction curves tended to approach the saturation plateau in high-throughput sequencing. The dominant microorganisms are consistent in two methods. Thus high-throughput sequencing can represent more comprehensive and the accurate microbial community structure on tobacco leaves.2. The dominant bacteria genera of all samples were Methylobacterium, Sphingomonas, Agrobacterium, Stenotrophomonas, Pseudomonas and Acinetobacter (these belong to Proteobacteria), Bacillus (belong to Firmicutes), and Sphingobacterium (belong to Bacteroidetes). A large number of dominant fungi sequences were not classified by high-throughput sequencing. The dominant fungi could be classified were Meyerozyma, Alternaria, Emericella, Aspergillus, Paecilomyces (belong to Ascomycota), Rhodotorula and Sporidiobolales (belong to Basidiomycota).3. The kind of microorganisms on flue-cured tobacco leaves were not changed during aging process. However the proportion of every microorganisms were changing all the time. No obviously changing rule was found in bacteria. At the same time, Basidiomycota increased while unclassified fungi decreased, however Ascomycota remain unchanged.