Differential Enhancement of Cigar Tobacco Leaf Aroma by Single-Strain Inoculation with Alcaligenes phenolicus and Bacillus subtilis

C5) from CTLs during air-curing. Single strain inoculation resulted in treatment-specific aroma compound changes: Z2 treatment was associated with enhanced diterpene compounds (notably neophytadiene and 1-heptacosanol), while C5 markedly increased fatty alcohol concentrations (2-hexyl-1-decanol, 9.67-fold) and nicotine levels. Mixed inoculation generally showed intermediate rather than synergistic effects. Variable importance in projection (VIP) analysis identified nicotine, neophytadiene, and nonadecatrienediol as the most discriminatory compounds among treatments. Microbial community analysis revealed that exogenous strain inoculation significantly altered indigenous microbiota composition and interaction patterns, with Z2 treatment associated with positive microbial co-occurrence patterns, while mixed inoculation displayed network characteristics suggestive of increased competitive interactions. Correlation analysis revealed strain-specific microbial-metabolite associations, though causal relationships require further validation. These findings suggest that single strain inoculation produces distinct metabolic profiles with potential for strain-specific tobacco aroma modulation.