bamboo shoots. 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 relative abundance of Firmicutes was higher in water-sealed treatment groups than in non-sealed treatment groups. Different organic acids selected different microbial taxa, and the growth of acid-sensitive Lactococcus and Weissella was inhibited throughout the fermentation period. Different initial organic acid concentrations selected biomarker taxa (Sphingomonas) with the ability to degrade organic pollutants. With tap water as the fermentation broth, Acinetobacter became the dominant bacterial genus, but it inhibited the production of flavor compounds. Streptococcus thermophilus and Lactobacillus bulgaricus from animal sources had no significant effect on fermentation. After inoculation with a five-in-one lactic acid bacteria fermentation agent, the abundance of Clostridium sensu stricto 1 as a biomarker in bamboo shoots was significantly increased, reaching a level 46.6 times that reported in the literature.

传统竹笋发酵工艺存在周期冗长、流程复杂且成品风味不均的不足。为解决上述问题，本研究考察了竹笋不同部位、不同发酵用水类型、是否水封处理、不同种类及初始浓度的有机酸，以及不同乳酸菌接种剂对竹笋发酵过程中微生物演替的影响。采用Illumina II高通量技术开展16S rRNA测序（16S rRNA sequencing），结合物种丰度、α多样性与β多样性指数，以及线性判别分析效应大小（linear discriminant analysis effect size, LEfSe）分析，结果显示所有检出微生物均隶属于厚壁菌门（Firmicutes）、蓝细菌门（Cyanobacteria）和变形菌门（Proteobacteria），其中厚壁菌门为优势菌门。水封处理组的厚壁菌门相对丰度显著高于非水封组。不同有机酸可筛选出不同的微生物类群，且在整个发酵周期内抑制酸敏感的乳球菌属（Lactococcus）与魏斯氏菌属（Weissella）的生长。不同初始有机酸浓度会筛选出具备有机污染物降解能力的生物标记类群鞘氨醇单胞菌属（Sphingomonas）。以自来水作为发酵液时，不动杆菌属（Acinetobacter）成为优势菌属，但会抑制风味物质的生成。来自动物源的嗜热链球菌（Streptococcus thermophilus）与保加利亚乳杆菌（Lactobacillus bulgaricus）对发酵过程无显著影响。接种五合一乳酸菌发酵剂后，作为竹笋发酵生物标记的梭菌属（Clostridium sensu stricto 1）的丰度显著提升，达到文献报道水平的46.6倍。