Metagenomics reveals microbial communities and functional differences during chili pepper (Capsicum frutescens L.) natural fermentation: Effects of brines and containers

Abstract

The study aimed to investigate the effect of fermentation brines and containers on the composition and functional dissimilarity of microbiota in fermented chili peppers: pool with fresh brine (PFB), pool with aged brine (PAB), jar with FB, and jar with AB. The results showed that brines had a greater impact on microbial diversity and fungal community structure than containers, whereas containers had a greater impact on bacterial community structure than brines. At the end of chili pepper fermentation, the dominant bacteria were unclassified_g__Pseudomonas, Lactobacillus_alimentarius, and Halococcus_thailandensis, whereas the dominant fungi were Pichia_membranifaciens and Wallemia_ichthyophaga. Based on the metagenomics functional analysis, the dominant bacteria and fungi were highly related to amino acid metabolism, glycerophospholipid metabolism, and most enzymes that promote carbohydrate substrate modulation. The fermented brines had a larger impact than containers on microbial function. Specifically, the use of FB was found to be beneficial for the biosynthesis of tetracycline, carotenoid, and isoflavonoid. On the other hand, AB was found to be beneficial for the biosynthesis of unsaturated fatty acids, amino acids, and various types of N-glycan.