To improve the quality of cigar tobacco leaves (CTLs) through microbial fermentation, an aroma-producing strain was identified as Bacillus safensis DMMJ-4, and the key fermentation parameters were optimized. Using gas chromatography–mass spectrometry (GC-MS) and electronic nose analysis combined with an orthogonal experimental design, the effects of fermentation temperature, inoculation concentration, and fermentation time on volatile flavor compounds (VFCs) were evaluated. The orthogonal test showed that the optimal process was CTLs fermented by Bacillus safensis DMMJ-4 at 40 °C with an inoculation concentration of 2 × 10 8 CFU/g for 21 days ( P < 0.05). The inoculation concentration exerted the strongest influence on VFCs, followed by fermentation temperature and fermentation time. A total of 57 VFCs were common to the two groups, while 67 VFCs were detected in Bacillus safensis DMMJ-4 and 60 were found in CK group. The GC-MS results showed that the total VFCs content in the Bacillus safensis DMMJ-4 group increased by 103.68% compared to that in the CK group. Phenethyl alcohol, lauryl alcohol, megastigmatrienone, geranylacetone, β-damascenone, and β-dihydroionone were significantly increased, while β-dihydroionone (ROAV=100) and nonanal (ROAV=100) made the greatest contribution in Bacillus safensis DMMJ-4 and CK groups, respectively. The sensory quality of the CTLs in the Bacillus safensis DMMJ-4 group was significantly higher than that in the CK group. This study integrated functional microorganisms and fermentation processes to enhance CTLs quality, which also provides a reference and valuable insights for industrial production. • Characterized one aroma-producing strain Bacillus safensis DMMJ 4. • Determined the optimal fermentation parameters using orthogonal experimental design. • Identified inoculation concentration as the primary fermentation factor. • Enhanced the flavor and sensory quality of cigar tobacco leaves fermented with DMMJ-4.
Qi et al. (2026) studied this question.