Sulfitobacter algicola sp. nov., isolated from green algae

Area of Science:

• Microbiology
• Bacteriology
• Marine Biology

Background:

• The genus Sulfitobacter comprises marine bacteria with diverse ecological roles.
• Characterization of novel bacterial species is crucial for understanding marine microbial ecosystems.
• Marine algae serve as habitats for various microbial communities.

Purpose of the Study:

• To isolate and characterize a novel bacterial strain from marine green algae.
• To determine the phylogenetic and phenotypic properties of the novel isolate.
• To propose a new species within the genus Sulfitobacter.

Main Methods:

• Isolation of strain 1151^T from marine green algae collected in Weihai, China.
• Physicochemical characterization including growth conditions, oxidase, and catalase tests.
• Phylogenetic analysis using 16S rRNA gene sequences.
• Genomic analysis including Average Nucleotide Identity (ANI) and DNA-DNA hybridization (DDH).
• Analysis of respiratory quinones, cellular fatty acids, and polar lipids.

Main Results:

• Strain 1151^T is a Gram-negative, aerobic, non-motile, oval-rod-shaped bacterium with light pink to tawny pigmentation.
• Optimal growth occurs at 33°C, pH 7.5–8.5, and 3% NaCl.
• Phylogenetic analysis places strain 1151^T within the genus Sulfitobacter, with highest 16S rRNA gene similarity to Sulfitobacter indolifex DSM 14862^T (96.6%).
• ANI (69.9%) and DDH (20.9%) values with S. indolifex DSM 14862^T support its distinct species status.
• Key fatty acids include C_18:1ω7c, C_20:1ω7c, and C_18:0; Q-10 is the sole respiratory quinone.
• DNA G+C content is 51.8 mol%; polar lipids include PG, PE, PC, and three unidentified lipids.

Conclusions:

• Strain 1151^T represents a novel species of the genus Sulfitobacter based on distinct phylogenetic and phenotypic characteristics.
• The proposed name for this novel species is Sulfitobacter algicola sp. nov.
• The type strain is 1151^T (=KCTC 72513^T =MCCC 1H00384^T).