Shifts in autochthonous microbial diversity and volatile metabolites during the fermentation of chili pepper (Capsicum frutescens L.)

To reveal the potential of core bacterial and fungal communities for aroma formation in the fermentation of chili pepper, shifts in microbial diversity and volatile metabolites during the 32-day fermentation process were measured using high-throughput sequencing and gas chromatography-mass spectrometry. Rosenbergiella and Staphylococcus were the dominant bacterial genera, where Hyphopichia and Kodamaea were the most abundant fungi, in fermented chili pepper. Sixteen differential volatile metabolites were detected in fermented and unfermented samples using differential metabolomics analysis. Nine strains from the genera Hyphopichia, Staphylococcus, Rosenbergiella, and Bacillus were isolated from fermented chili pepper. The correlation of dominant microorganisms with key odorants by Spearman correlation and two-way orthogonal partial least squares analysis indicated that Hyphopichia exhibited a significant positive correlation with the formation of 11 key odorants. These findings enhance our understanding of the core functional bacterial and fungal genera involved in the production of desirable flavors in fermented chili pepper.

Automated summary

Through high-throughput sequencing and gas chromatography-mass spectrometry analysis of the 32-day fermentation process of chili peppers, dominant bacterial genera such as Rosenbergiella and Staphylococcus, and abundant fungi genera such as Hyphopichia and Kodamaea were identified. Additionally, sixteen differential volatile metabolites were detected, and nine strains from different genera were isolated from fermented chili peppers. Further analysis indicated a significant positive correlation between Hyphopichia and the formation of 11 key odorants, enhancing our understanding of core functional bacterial and fungal genera involved in the desirable flavor production in fermented chili peppers.