Impact of microbial communities, metabolic profiles, and metabolites in sour bamboo shoot fermentation with different lactic acid bacteria: Insights from metagenomics and untargeted metabolomics

• 1 Organic acids and derivatives were most prevalent in LRS (86 compounds). • 2 LPS contained the highest number of organoheterocyclic compounds (86). • 3 Phenylalanine and L-proline significantly decreased in PPS. • 4 Isoleucine and tryptophan were markably reduced in LPS. • 5 LRS had the greatest number of genes for pyruvate metabolism (603 genes). The role of different lactic acid bacteria (LAB) in shaping microbial communities, metabolites, and metabolic functions during sour bamboo shoot fermentation remains unclear. This study examines the changes in metabolites, microbial communities, and functional differences in sour bamboo shoots fermented with Lactiplantibacillus plantarum (LPS), Lacticaseibacillus rhamnosus (LRS), and Pediococcus pentosaceus (PPS). Untargeted metabolomics revealed decreases in phenylalanine and L-proline in PPS, while isoleucine and tryptophan were reduced in LPS. Organic acids and derivatives were most prevalent in LRS (86 compounds), while LPS contained the highest number of organoheterocyclic compounds (86). Metagenomics revealed Ascomycota as the dominant phylum in PPS, while both Firmicutes and Ascomycota prevailed in LPS, and Proteobacteria and Firmicutes in LRS. Geotrichum and Galactomyces are the dominant genera in PPS, comprising 54.4% and 25.3% of the microbial community, respectively, while Lactiplantibacillus predominates in both LPS and LRS, significantly influencing GH13_31 in LRS with a 94.59% contribution. Metabolic reconstruction analysis showed that LRS had the greatest number of genes for pyruvate metabolism (603 genes), while PPS had the fewest genes (63) involved in phenylalanine, tyrosine, and tryptophan biosynthesis. These findings provide valuable insights for optimizing microbial starter cultures in the fermentation of sour bamboo shoots and enhancing product quality.