肠道菌群多样性及其潜在益生菌的筛选鉴定

INTESTINAL MICROBIOTA DIVERSITY AND THE SCREENING AND IDENTIFICATION OF POTENTIAL PROBIOTICS IN PSEUDOGOBIO VAILLANTI

  • 摘要: 为研究似鮈(Pseudogobio vaillanti)肠道菌群的多样性和作为益生菌潜力, 采用高通量测序技术对肠道菌群16S rRNA基因进行分析, 进一步对分离菌株的抑菌效果、产酶能力、耐受能力、安全性进行测定, 筛选出潜在益生菌, 并进行菌种鉴定。结果表明, 似鮈肠道中优势菌门为厚壁菌门、拟杆菌门和变形菌门, 共占比79.98%; 优势菌纲为拟杆菌纲、梭杆菌纲、芽孢杆菌纲和γ-变形菌纲, 共占比74.69%; 相对丰度排名前10的菌属为乳杆菌属、阿克曼氏菌属、狭义梭菌属、不动杆菌属、拟杆菌属、杜氏菌属、UCG-005菌属、毛螺菌科NK4A136群、理研菌科RC9群、支原体属, 共占比28.77%。筛选得到2株抑菌和产酶效果好的菌株S4和S5, 它们在pH 2.0—6.0的人工胃液、pH 6.8的人工肠液及0.3%、0.5%的胆盐中存活率均大于57%; 它们既无耐药性, 也无溶血性; S4和S5均为贝莱斯芽孢杆菌。因此, 似鮈肠道菌群具有多样性, 其中贝莱斯芽孢杆菌S4和S5是抑菌效果好、产酶和耐受能力强、安全性能高的潜在益生菌。研究可为似鮈肠道微生物及益生菌的研发提供基础数据。

     

    Abstract: In order to understand the diversity of intestinal microbiota in Pseudogobio vaillanti and their potential as probiotics, high throughput sequencing technology was used to analyze the 16S rRNA gene of intestinal microbiota. Furthermore, the bacteriostatic effect, enzyme production capability, tolerance, and safety of the isolated strains were determined to identify potential probiotics, followed by strain identification. The results showed that Firmicutes, Bacteroidota, and Proteobacteria were the dominant phylum in the intestinal tract of Pseudogobio vaillanti, accounting 79.98% of the total microbiota. The dominant classes included Bacteroidia, Clostridia, Bacilli, and Gammaproteobacteria, accounting for 74.69%. The top 10 genera with the highest relative abundance were Lactobacillus, Akkermansia, Clostridium_sensu_stricto, Acinetobacter, Bacteroides, Dubosiella, UCG-005, Lachnospiraceae_NK4A136_group, Rikenellaceae_RC9_gut_group, and Mycoplasma, collectively accounting for 28.77 %. Two strains, S4 and S5, exhibited notable antibacterial and enzyme-producing effects. These strains exhibited survival rates greater than 57% in artificial gastric fluid with pH levels ranging from 2.0 to 6.0, artificial intestinal fluid with pH 6.8, and 0.3% to 0.5% bile salts. They showed no drug resistance or hemolytic activity and were identified as Bacillus velezensis. Therefore, the intestinal microbiota of Pseudogobio vaillanti is diverse, and Bacillus velezensis strains S4 and S5 are promising probiotics due to their antibacterial properties, robust enzyme production, tolerance, and high safety performance. This study provides a solid foundation for further research into fish intestinal microbiota diversity and offers a theoretical basis for the development of probiotics and healthy aquaculture practices.

     

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