[Objective] To improve the flavour quality of redried tobacco leaves and explore new microbial resources for fermentation. [Methods] A yeast strain PT-1 with pronounced fruit-aroma-producing ability was isolated and screened from commercially available Kyoho grapes. It was identified as Debaryomyces hansenii through rDNA-ITS sequence analysis. This strain was applied to the fermentation of redried tobacco leaves. By treating the tobacco leaves with a yeast suspension at an application rate equivalent to 4% of the tobacco leaf mass, we systematically evaluated the effects on the chemical composition, sensory quality, and microbial community structure of the tobacco leaves. [Results] After inoculation with D. hansenii, the total sugar and reducing sugar contents in tobacco leaves increased by 0.85% and 0.46%, respectively, while the total alkaloids and total nitrogen decreased by 0.07% and 0.05%, respectively. Sensory evaluation results indicated that the treatment group was superior to the control group in terms of aroma quality, sweetness, and aftertaste. High-throughput sequencing results showed that the bacterial diversity on the surface of tobacco leaves remained relatively stable after inoculation, while the fungal diversity significantly decreased. The microbial community structure was markedly simplified, with Debaryomyces becoming the overwhelmingly dominant genus (99.66%). Correlation analysis showed that D. hansenii was significantly positively correlated with total sugar, reducing sugar, aroma quality, and sweetness, and was negatively correlated with total nitrogen, total alkaloids, and strength, suggesting a potential association with improved tobacco leaf quality. [Conclusion] This study expands the pool of aroma-producing yeast resources and verifies the application potential of D. hansenii in tobacco leaf fermentation. The process is simple and low-cost, with a clear flavour-modulating effect. These findings provide a theoretical basis and a practical foundation for constructing an efficient and controllable functional microbial fermentation system.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |