Analysis And Application Of The Microbiota On Aging Tobacco

It has been known that microbes play a key role in the process of plant aging.However,the current research only focuses on functional strains,and there is no research based on microbiota has been reported.In this study,the typical aging plant of tobacco was used as experimental material,and the microbiota collection,amplification,evaluation and application from aging tobacco were investigated.Aging K326 tobacco leaves with WDC3 F grade from Yuxi were used in this study.Firstly,an effective microbiota-collection method based on SDS as assistant separator was established and optimized,and the collecting rate increased nearly 6 folds than traditional one.According to the nutritional components of tobacco aging,the conditions for amplifying bacterial biota of tobacco were explored.The results showed that,the modified LB medium supplemented with tobacco leaf extract could not only enriched the bacterial biota from the surface of tobacco leaf nearly 100 times,higher than traditional method,but also can preserve the integrity of bacterial biota at 15?.Meanwhile,the diversity of bacterial biota before and after amplification were evaluated and analyzed.The results showed that there was no significant bias of culturable bacterial biota before and after amplification,all identified strains belonged to Bacillus and Atlantis genuses,but at the species level,the Atlantibacter hermannii species was absent in amplified bacterial biota.The analysis of culture-independent showed that the bacterial biota from the surface of aging tobacco leaves presented significant changes after bacterial biota amplification.At phylum level,total of four phyla of Proteobacteria,Bacteriodetes,Firmicutes and Actinobacteriabacteria have been found,but only Proteus and Bacteroides phyla were remained in amplified bacterial biota.At the end of this study,the amplified bacterial biota was applied on K326 tobacco leaves(Aging conditions: 24?,65% humidity)with 2% concentration(V/M).The total enzyme activity,chemical composition and sensory quality of aged tobacco leaves were investigated.The results showed that the enzymatic activity of the group added with bacterial biota was generally improved,in which the protease activity increased nearly 81%.The chemical composition analysis also showed that the addition of bacterial biota enhanced the degradation of total sugar,reducing sugar,starch and total alkaloids in tobacco leaves,and the degradation rates were 4.6,3.17,1.04 and 8 times higher than those in the control group,respectively.The final sensory quality assessment confirmed that the addition of bacterial biota significantly improved the quality of tobacco leaves.Bacterial biota collection from tobacco leaves,and its amplification,evaluation and artificial aging promotion have been systematically investigated in this study.It has been demonstrated that the amplification and application of bacterial biota on aging tobacco could effectively improve the aging speed and quality of tobacco,which will benefit on application of bacterial biota in tobacco industry.