Multi-omics dissection of phyllospheric microbial succession and volatile flavor compound formation in cigar tobacco...

Fermentation plays a critical role in determining the quality and aroma of cigar tobacco; however, the interactions between phyllospheric microbial succession and volatile flavor compound (VFC) formation remain insufficiently understood. This study aimed to elucidate the associations between microbial community dynamics and flavor development during tobacco fermentation using a multi-omics approach.

Distinct stage-dependent shifts in microbial communities were observed across unfermented (F1), mid-fermentation (F2), and final-fermentation (F3) stages. Bacterial diversity showed a 'first-decrease-then-increase' trend, with Staphylococcus dominating mid-fermentation (relative abundance > 97%) and keystone genera (Methylobacterium-Methylorubrum, Aerococcus) enriching at the final stage. Fungal communities were persistently dominated by Aspergillus throughout fermentation. Volatile metabolomics identified 47 differentially abundant flavor compounds, with aldehydes (e.g. benzaldehyde, nonanal) and alcohols (e.g. 1-pentanol) significantly enriched post-fermentation. Correlation analyses revealed stronger associations between bacterial communities and VFCs compared to fungi, with Aerococcus showing significant positive correlations with key upregulated compounds (P < 0.05). Functional prediction suggested that carbohydrate, amino acid, and lipid metabolism pathways may contribute to VFC formation.

This study demonstrates that microbial succession is closely associated with chemical transformation and flavor development during cigar tobacco fermentation. Bacterial taxa, particularly Aerococcus, may play important roles in shaping volatile profiles. These findings provide a theoretical basis for future microbial regulation strategies aimed at improving fermentation quality. © 2026 Society of Chemical Industry.