Paracoccus litorisediminis sp. nov., isolated from a tidal flat

Area of Science:

• Microbiology
• Bacteriology
• Taxonomy

Background:

• The genus Paracoccus encompasses diverse Gram-negative bacteria with significant roles in biogeochemical cycles.
• Exploring microbial diversity in marine environments like tidal flats is crucial for discovering novel species with unique metabolic capabilities.

Purpose of the Study:

• To characterize a novel bacterial isolate, strain GHD-05^T, obtained from a Yellow Sea tidal flat.
• To determine the taxonomic position of strain GHD-05^T within the genus Paracoccus and propose a new species if distinct.

Main Methods:

• Isolation and cultivation of strain GHD-05^T under specific environmental conditions (temperature, pH, salinity).
• Phylogenetic analysis using 16S rRNA gene sequences.
• Determination of chemotaxonomic markers, including predominant ubiquinone and major fatty acids.
• Analysis of polar lipid profiles.
• DNA G+C content determination and DNA-DNA hybridization experiments.

Main Results:

• Strain GHD-05^T is a Gram-negative, non-spore-forming, non-motile coccoid or short rod, growing optimally at 30°C, pH 7.0-8.0, and 2.0% NaCl.
• Phylogenetic analysis placed strain GHD-05^T within the genus Paracoccus, with high 16S rRNA gene similarity to P. aestuariivivens, P. limosus, P. laeviglucosivorans, and P. marinus.
• Chemotaxonomic data (Q-10, C18:1ω7c) and polar lipid profiles were consistent with the genus Paracoccus.
• Low DNA-DNA relatedness (<32%) with related Paracoccus species confirmed its genetic distinctiveness.
• The DNA G+C content was 64.1 mol%.

Conclusions:

• Strain GHD-05^T exhibits distinct phylogenetic and genotypic characteristics differentiating it from known Paracoccus species.
• Based on phenotypic, phylogenetic, and genetic data, strain GHD-05^T represents a novel species, proposed as Paracoccus litorisediminis sp. nov.
• The type strain for this new species is GHD-05^T (=KCTC 52978^T=NBRC 112902^T).