The bacterial succession and its role in flavor compounds formation during the fermentation of cigar tobacco leaves

Hongyang Si; Kun Zhou; Tingyi Zhao; Bing Cui; Fang Liu; Mingqin Zhao

doi:10.1186/s40643-023-00694-9

The bacterial succession and its role in flavor compounds formation during the fermentation of cigar tobacco leaves

Bioresour Bioprocess. 2023 Oct 31;10(1):74. doi: 10.1186/s40643-023-00694-9.

Authors

Hongyang Si¹, Kun Zhou¹, Tingyi Zhao¹, Bing Cui², Fang Liu¹, Mingqin Zhao³

Affiliations

¹ College of Tobacco Science, Flavors and Fragrance Engineering & Technology Research Center of Henan Province, Henan Agricultural University, No.218 Ping An Avenue, Zhengdong New District, Zhengzhou, 450046, Henan, China.
² College of Tobacco Science, Flavors and Fragrance Engineering & Technology Research Center of Henan Province, Henan Agricultural University, No.218 Ping An Avenue, Zhengdong New District, Zhengzhou, 450046, Henan, China. bingcui@henau.edu.cn.
³ College of Tobacco Science, Flavors and Fragrance Engineering & Technology Research Center of Henan Province, Henan Agricultural University, No.218 Ping An Avenue, Zhengdong New District, Zhengzhou, 450046, Henan, China. zhaomingqin@henau.edu.cn.

Abstract

Fermentation is the key process required for developing the characteristic properties of cigar tobacco leaves, complex microorganisms are involved in this process. However, the microbial fermentation mechanisms during the fermentation process have not been well-characterized. This study investigated the dynamic changes in conventional chemical composition, flavor compounds, and bacterial community during the fermentation of cigar tobacco leaves from Hainan and Sichuan provinces in China, as well as the potential roles of bacteria. Fermentation resulted in a reduction of conventional chemical components in tobacco leaves, with the exception of a noteworthy increase in insoluble protein content. Furthermore, the levels of 10 organic acids and 19 amino acids showed a significant decrease, whereas the concentration of 30 aromatic substances exhibited a unimodal trend. Before fermentation, the bacterial community structures and dominant bacteria in Hainan and Sichuan tobacco leaves differed significantly. As fermentation progressed, the community structures in the two regions became relatively similar, with Delftia, Ochrobactrum, Rhodococcus, and Stenotrophomonas being dominant. Furthermore, a total of 12 functional bacterial genera were identified in Hainan and Sichuan tobacco leaves using bidirectional orthogonal partial least squares (O2PLS) analysis. Delftia, Ochrobactrum, and Rhodococcus demonstrated a significant negative correlation with oleic acid and linoleic acid, while Stenotrophomonas and Delftia showed a significant negative correlation with undesirable amino acids, such as Ala and Glu. In addition, Bacillus showed a positive correlation with benzaldehyde, while Kocuria displayed a positive correlation with 2-acetylfuran, isophorone, 2, 6-nonadienal, and β-damascenone. The co-occurrence network analysis of microorganisms revealed a prevalence of positive correlations within the bacterial network, with non-abundant bacteria potentially contributing to the stabilization of the bacterial community. These findings can improve the overall tobacco quality and provide a novel perspective on the utilization of microorganisms in the fermentation of cigar tobacco leaves.

Keywords: Bacterial community; Cigar tobacco leaves; Co-occurrence network; Fermentation; Flavor substances.

Abstract

Grants and funding