Phyllosphere microbial community of cigar tobacco and its corresponding metabolites

Abstract

Cigar is made of a typical fermented tobacco where the microbiota inhabits within an alkaline environment. Our current understanding on cigar fermentation is far from thorough. This work employed both high-throughput sequencing and chromatography-mass spectrometric technologies to provide new scientific reference for this specific fermented system. Typical cigar samples from different regions (the Caribbeans, South America, East Asia, and Southeast Asia) were investigated. The results show that <i>Firmicutes</i>, <i>Actinobacteria</i>, <i>Proteobacteria, Ascomycota</i>, and <i>Basidiomycota</i> were the predominant phyla in the cigar samples. Rather than the fungal community, it was the bacterial community structures that played vital roles to differentiate the cigar from different regions: <i>Staphylococcus</i> was the dominant genus in the Americas; <i>Bacillus</i> was the dominant genus in Southeast Asia; while in East Asia, there was no dominant genus. Such differences in community structure then affected the microflora metabolism. The correlation between microbiota and metabolites revealed that <i>Aspergillaceae</i>, <i>Cercospora</i>, and <i>Staphylococcus</i> were significantly correlated with sclareolide; <i>Bacillus</i> were positively associated with isophorone. <i>Alcaligenaceae</i> was significantly and positively correlated with L-nicotine and hexadecanoic acid, methyl ester. GRAPHICAL ABSTRACT.