Development of a mixed bacterial strain for fermentation of Shaanxi tobacco leaves based on metagenomic technology

WANG Zhen; XU Yijuan; LIU Chen; SONG Kai; WEI Jinbin; ZANG Zhipeng; HU Wei; MAO Duobin

doi:10.12187/2025.06.009

Abstract：[Objective]To enhance the sensory quality and industrial usability of Shaanxi-origin tobacco leaves.[Methods]Metagenomic sequencing was employed to characterize the dynamic shifts in surface microbiota of tobacco filaments during Bacillus thuringiensis 116 fermentation.This approach aimed to elucidate the functional roles of dominant strains and their correlations with aroma compound profiles,facilitating the identification of optimal mixed-strain fermentation formulations.[Results]During B.thuringiensis 116 fermentation of SXZL tobacco filaments,the dominant bacterial genera included Sphingomonas,Pseudomonas,Enterobacter,Kosakonia,Pantoea,and Methylobacterium.Positive correlations were observed between the relative abundances of Bacillus,B.terrae,Enterobacter,and Kosakonia and the concentrations of 3-oxo-α-ionol,megastigmatrienone,and damascenone.Bacillus abundance also showed positive correlations with B.terrae,Enterobacter,and Kosakonia.Compared to single-strain fermentation,co-fermentation with B.thuringiensis 116 and Bacillus Y7 improved smoke intensity and quality,enhanced aroma volatility,increased sweetness,and refined aftertaste comfort.The concentrations of damascenone,scopoletin,and 3-oxo-α-ionol increased by 140.10%,133.51%,and 104.51%,respectively.Significant elevations were also noted in the relative changes of 3-oxo-α-ionol,4-hydroxy-β-dihydrodamascone,curcumin,and kauraldehyde.[Conclusion]Mixed-strain fermentation significantly increases aroma compound concentrations in tobacco filaments and improves the sensory quality of cigarettes.