Bacteroides faecalis sp. nov., isolated from human faeces

Area of Science:

• Microbiology
• Bacteriology
• Genomics

Background:

• The human gut microbiome harbors diverse bacterial species.
• Accurate classification of novel bacteria is crucial for understanding microbial ecology and function.

Purpose of the Study:

• To characterize and classify a novel bacterial strain isolated from human feces.
• To determine the phylogenetic and genomic relatedness of the novel isolate to known species.

Main Methods:

• Isolation and cultivation of anaerobic bacteria from human fecal samples.
• Phylogenetic analysis using 16S rRNA gene sequences.
• Whole-genome sequencing for DNA G+C content and average nucleotide identity (ANI) calculations.
• Fatty acid and respiratory quinone analysis.
• Fermentation product analysis.

Main Results:

• A novel Gram-negative, strictly anaerobic, non-motile, non-spore-forming rod, strain KGMB02408^T, was isolated.
• Phylogenetic analysis placed the strain within the genus Bacteroides, closely related to Bacteroides faecichinchillae (96.5% 16S rRNA gene sequence similarity).
• Genomic analysis showed a DNA G+C content of 39.5% and an ANI value of 93.8% with B. faecichinchillae.
• Major fatty acids included anteiso-C_15:0, iso-C_17:0-OH, summed feature 11, and C_16:0. Menaquinones MK-8 and MK-10 were predominant.
• Glucose fermentation yielded lactic, acetic, and formic acids.

Conclusions:

• Strain KGMB02408^T represents a novel species of the genus Bacteroides.
• The proposed new species belongs to the family Bacteroidaceae.
• The type strain is KGMB02408^T (=KCTC 15687^T=DSM 107828^T).