Bacterial diversities on unaged and aging flue-cured tobacco leaves estimated by 16S rRNA sequence analysis.

Flue-cured tobacco leaves (FCTL) contain abundant bacteria, and these bacteria play very important roles in the tobacco aging process. However, bacterial communities on aging FCTL are not fully understood. In this study, the total microbial genome DNA of unaged and aging flue-cured tobacco K326 were isolated using a culture-independent method, and the bacterial communities were investigated by restriction fragment length polymorphism analysis. Comparison of the number of operational taxonomic units (OTUs) between the cloned libraries from the unaged and aging FCTL showed that the microbial communities between the two groups were different. Fifty and 42 OTUs were obtained from 300 positive clones in unaged and aging FCTL, respectively. Twenty-seven species of bacteria exist in both the unaged and aging FCTL, Bacillus spp. and Pseudomonas spp. were two dominant genera in FCTL. However, 23 bacterial species were only identified from the unaged FCTL, while 15 species were only identified from the aging FCTL. Interestingly, more uncultured bacteria species were found in aging FCTL than in unaged FCTL.