Effects of Different Bacillus Treatments on Aging Quality of Tobacco Leaves

This study explored the role of microbial fermentation in tobacco leaf aging using three aroma-producing bacteria (Bacillus licheniformis, Bacillus altitudinis, and Bacillus velezensis) inoculated at three concentrations (10⁶, 10⁹, 10¹² CFU/mL). After 18 months of aging, chemical and volatile compounds were analyzed. Results indicated that inoculation levels had no significant impact on chemical or volatile components. However, comparative analysis revealed significant compositional differences between the inoculated and control groups. Compared to the control group, bacterial-inoculated tobacco leaves exhibited decreased contents of total sugars, reducing sugars, and nicotine, with sugars declining over time. Additionally, bacterial fermentation increased total volatile compounds, with B. velezensis yielding the highest (490.45 ± 12.92 μg/g) and B. altitudinis the lowest (304.62 ± 12.81 μg/g). Principal component analysis (PCA) further confirmed distinct volatile profiles among treatments. Compared to the control group, microbial fermentation improved the sensory qualities of aged tobacco. This study offers essential insights into developing novel biological flavor-enhancement technologies for tobacco, providing theoretical support for optimizing aging processes and laying the foundation for innovative bioprocessing techniques.