Sphingomonas oryzagri sp. nov., isolated from a rice field

Area of Science:

• Microbiology
• Bacteriology
• Genomics

Background:

• The genus Sphingomonas comprises diverse bacteria with significant roles in various environments.
• Accurate taxonomic classification of novel isolates is crucial for understanding microbial diversity and function.

Purpose of the Study:

• To characterize and classify a novel bacterial strain, MAHUQ-71T, isolated from rice field soil.
• To determine the phylogenetic and genomic relatedness of strain MAHUQ-71T to other Sphingomonas species.

Main Methods:

• Isolation and cultivation of bacteria from soil samples.
• Phenotypic characterization including Gram staining, motility, growth conditions, and biochemical tests.
• 16S rRNA gene sequencing for phylogenetic analysis.
• Genome sequencing and analysis, including Average Nucleotide Identity (ANI) and digital DNA-DNA hybridization (dDDH).
• Chemotaxonomic analyses (fatty acid and polar lipid profiles, isoprenoid quinones).

Main Results:

• Strain MAHUQ-71T is a Gram-negative, aerobic, short rod-shaped, motile bacterium.
• It exhibits optimal growth at 15-37°C, pH 5.0-10.0, and up to 3.0% NaCl.
• Phylogenetic analysis based on 16S rRNA gene sequences places it within the genus Sphingomonas, closely related to Sphingomonas chungangi.
• Genomic analyses (ANI and dDDH values) confirm its distinctness from known species.
• Chemotaxonomic data align with the genus Sphingomonas, with specific fatty acid and polar lipid profiles.

Conclusions:

• Strain MAHUQ-71T represents a novel species within the genus Sphingomonas.
• The proposed name for this new species is Sphingomonas oryzagri sp. nov.
• The type strain is MAHUQ-71T (=KACC 22252T=CGMCC 1.19065T).