# Aestuariibius violaceus sp. nov., isolated from a marine limpet Cellana toreuma

## TL;DR

A new marine bacterium, Aestuariibius violaceus, was discovered in a Korean limpet and distinguished from related species through genetic and biochemical analysis.

## Contribution

The discovery and taxonomic characterization of a novel bacterial species, Aestuariibius violaceus, isolated from a marine limpet.

## Key findings

- Strain 2305UL40-4T has unique physiological traits and genetic differences from Aestuariibius insulae.
- The new species utilizes d-raffinose, d-ribose, and d-xylose, distinguishing it from related strains.
- The DNA G+C content and fatty acid profile support its classification as a new species.

## Abstract

A novel bacterium, designated strain 2305UL40-4T, was isolated from Cellana toreuma (a Korean limpet) collected from Ulleung Island, Republic of Korea. The cells were Gram-stain-negative, aerobic, rod-shaped (0.5–0.9 µm×1.5–2.2 µm) and non-motile. Growth was observed at 22–36 °C (optimum 25–30 °C), pH 6–8 (optimum pH 7) and in the presence of 0.5–4.0% (w/v, optimum 2.0%) NaCl. The 16S rRNA gene sequence analysis revealed that strain 2305UL40-4T shared 97.4% similarity with Aestuariibius insulae DBTF-13T. The average nucleotide identity value between the two strains was 76.5%, and the digital DNA–DNA hybridization value was 19.0%. Both values are well below the species delineation thresholds. The DNA G+C content of strain 2305UL40-4T was 63.8 mol%. The major fatty acids were C16 : 0, C18 : 0 and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). Major polar lipids included phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine, five unidentified aminolipids and fifteen unidentified lipids. Ubiquinone-10 was the predominant quinone. The new strain differs from A. insulae in its ability to utilize d-raffinose, d-ribose and d-xylose. Based on these polyphasic taxonomic characteristics, strain 2305UL40-4T is proposed as a novel species within the genus Aestuariibius, with the name Aestuariibius violaceus sp. nov. The type strain is 2305UL40-4T (=KCCM 43505T=MCCC 1K09164T).