Study on the mechanism of improving fermentation quality of cigar wrapper leaves by Bacillus velezensis

ZHANG Tongtong; ZHAO Jun; YU Jun; LI Linwei; HUANG Chenyi; YANG Chunlei; CHEN Xiong; YAO Lan

doi:10.12187/2023.06.012

Abstract：The differences and their correlation in conventional chemical composition,fragrance-causing components and microbial community structure of cigar wrapper leaves before and after fermentation as well as metabolic pathway change were analyzed in this study to explore the mechanism of B.velezensis H1 on the flavoring and quality enhancement of cigar wrapper leaves.The results showed that relative contents of nicotine,total nitrogen and potassium were significantly changed after adding exogenous B.velezensis H1.The types and the content of aroma substances in cigar wrapper leaves treated with B.velezensis H1 increased significantly,such as phytol,geranylacetone and neophytadiene,which could effectively improve the quality of flue gas to be pure and mild.After fermentation,the bacterial diversity on the surface of cigar wrapper leaves changed significantly,and the number of OTUs was increased after B.velezensis Hl inoculation.The bacterial community structure and dominant flora on the surface of tobacco leaves were changed.The dominant phylum changed from Firmicutes to Actinobacteriota after treated with B.velezensis Hl.The dominant genus evolved from Staphylococcus to Staphylococcus,Yaniella,unclassified_f_Micrococcaceae.The top five metabolic pathways of significant changes due to microbial community structure transformation were global and overview maps,carbohydrate metabolism,amino acid metabolism,metabolism of cofactors and vitamins,and energy metabolism.The results of correlation analysis showed that key substances such as reducing sugar,total nitrogen,nicotine,chlorine,total sugar,and potassium were greatly influenced by the bacterial community of cigar wrapper leaves.Generation of phenylethanol was related to Staphylococcus,Corynebacterium,and Oceanobacillus.Geranylacetone formation was closely related to Micrococcus,Oceanobacillus,and Enteractinococcus.