Nakamurella leprariae sp. nov., isolated from a lichen sample

Area of Science:

• Microbiology
• Bacteriology
• Taxonomy

Background:

• Actinobacteria are a diverse group of bacteria known for their metabolic capabilities.
• Lichen-associated microorganisms represent a largely unexplored source of novel bacterial species.
• Accurate taxonomic classification is crucial for understanding microbial diversity and function.

Purpose of the Study:

• To isolate and characterize a novel actinobacterium from a lichen sample.
• To determine the phylogenetic and taxonomic position of the novel isolate.
• To propose a new species within the genus Nakamurella.

Main Methods:

• Polyphasic taxonomic approach including phenotypic, chemotaxonomic, and phylogenetic analyses.
• 16S rRNA gene sequencing for phylogenetic placement.
• Genome sequencing for average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) calculations.
• Analysis of polar lipids, menaquinones, fatty acids, peptidoglycan, and whole-cell sugars.

Main Results:

• A novel Gram-stain-positive, aerobic, coccus-shaped actinobacterium, strain YIM 132084T, was isolated from a Lepraria sp. lichen.
• Chemotaxonomic analysis revealed characteristic polar lipids, menaquinone (MK-8(H4)), and fatty acids (anteiso-C15:0, anteiso-C17:0, iso-C15:0, iso-C16:0).
• Phylogenetic analysis based on 16S rRNA gene sequences showed highest similarity (97.7%) to Nakamurella flavida and Nakamurella flava. ANI (76.1%) and dDDH (20.9%) values supported its distinction as a new species.
• The G+C content of the genomic DNA was 72.4 mol%.

Conclusions:

• Strain YIM 132084T represents a novel species of the genus Nakamurella.
• The proposed name for this new species is Nakamurella leprariae sp. nov.
• This discovery expands the known biodiversity of the Nakamurella genus and highlights lichens as a source of novel microorganisms.