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Updated: Aug 9, 2026
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Isolation and Characterization of the Natural Microbiota of the Model Nematode Caenorhabditis elegans
Published on: August 17, 2022
Bacteroides finegoldii sp. nov., isolated from human faeces
Mohammad Abdul Bakir1, Maki Kitahara1, Mitsuo Sakamoto1
1Microbe Division/Japan Collection of Microorganisms, RIKEN BioResource Center, Wako, Saitama 351-0198, Japan.
Summary
Two novel human gut bacteria strains, Bacteroides finegoldii sp. nov., were identified. These bacteria, isolated from fecal microbiota, represent a new species within the Bacteroides genus.
Area of Science:
- Microbiology
- Bacteriology
- Human Gut Microbiota
Background:
- Human gut microbiota plays a crucial role in health.
- The genus Bacteroides comprises important anaerobic bacteria residing in the human gut.
- Characterization of novel bacterial species enhances our understanding of microbial diversity.
Purpose of the Study:
- To isolate and characterize novel bacterial strains from human fecal microbiota.
- To determine the phylogenetic and taxonomic position of the isolated strains.
- To propose a new species within the genus Bacteroides.
Main Methods:
- Isolation of bacteria using polyamine-deficient medium.
- Phylogenetic analysis based on 16S rRNA gene sequencing.
- DNA-DNA hybridization and phenotypic characterization.
- Determination of G+C content and major fatty acid composition.
Main Results:
- Two Gram-negative, anaerobic, rod-shaped bacterial strains (199T and 176) were isolated.
- Phylogenetic analysis placed the strains within the genus Bacteroides.
- DNA-DNA hybridization (89% relatedness) and phenotypic data confirmed the strains represent a single, novel species.
- The new species showed less than 23% DNA-DNA relatedness with closely related species like Bacteroides thetaiotaomicron and Bacteroides ovatus.
Conclusions:
- A novel species, Bacteroides finegoldii sp. nov., is proposed, with strain 199T as the type strain.
- This discovery expands the known diversity of the human gut Bacteroides genus.
- Bacteroides finegoldii is distinct from its closest phylogenetic neighbors.
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