Dynamic changes in microbiota during fermentation of bamboo shoots under varying conditions in Guangxi, China

The traditional fermentation process for bamboo shoots is long, complex, and yields a product with a non-uniform flavor. To address these issues, we determined the effects of using different parts of the bamboo shoot, different types of fermentation water, water-sealing or not, different types and initial concentrations of organic acids, and different lactobacillus inocula on microbial succession during the fermentation of bamboo shoots. 16S rRNA sequencing was performed using Illumina II high-throughput technology. Species abundance, α-, and β-diversity indices, and linear discriminant analysis effect size (LEfSe) analysis revealed that all detected microorganisms were members of the phyla Firmicutes, Cyanobacteria, and Proteobacteria, of which Firmicutes were dominant.

The effects of these variables on microbial succession were evaluated through 16S rRNA sequencing using Illumina II high-throughput technology. Species abundance, α- and β-diversity indices, and linear discriminant analysis effect size (LEfSe) analysis were used to identify and analyze the microbial community.

The microbial community was dominated by the phyla Firmicutes, Cyanobacteria, and Proteobacteria, with Firmicutes being the most abundant. The relative abundance of Firmicutes was higher in water-sealed treatment groups than in non-sealed groups. Different organic acids selected specific microbial taxa, and the growth of acid-sensitive Lactococcus and Weissella was inhibited throughout fermentation. Different initial concentrations of organic acids selected biomarker taxa, such as Sphingomonas, which has the ability to degrade organic pollutants. When tap water was used as the fermentation broth, Acinetobacter became the dominant genus but inhibited the production of flavor compounds. Streptococcus thermophilus and Lactobacillus bulgaricus, derived from animal sources, had no significant effect on fermentation. Inoculation with a five-in-one lactic acid bacteria fermentation agent significantly increased the abundance of Clostridium sensu stricto 1, reaching a level 46.6 times that reported in the literature.

This study shows that various factors, including water-sealing, organic acids, and microbial inoculation, have significant effects on microbial succession and the flavor profile of fermented bamboo shoots. These findings suggest that optimizing these parameters can improve the consistency and flavor quality of the product.