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Demequina activiva sp. nov., isolated from a tidal flat
Sooyeon Park1, Yong-Taek Jung1,2, Sung-Min Won1
1Department of Food Science and Biotechnology, Sungkyunkwan University, Jangan-gu, Suwon, South Korea.
Summary
A novel bacterial species, Demequina activiva, was discovered in South Korean tidal flats. This Gram-positive bacterium expands the known diversity within the Demequina genus.
Area of Science:
- Microbiology
- Bacteriology
- Phylogenetics
Background:
- The genus Demequina comprises bacteria found in marine environments.
- Understanding bacterial diversity in tidal flats is crucial for marine ecosystem studies.
Purpose of the Study:
- To isolate and characterize a novel bacterial strain from a tidal flat sediment.
- To determine the phylogenetic and genetic distinctiveness of the novel strain within the Demequina genus.
Main Methods:
- Isolation and cultivation of bacterial strain BS-12M(T) from tidal flat sediment.
- Physicochemical characterization including optimal growth conditions (temperature, pH, salinity).
- Phylogenetic analysis based on 16S rRNA gene sequencing.
- Determination of peptidoglycan type, major menaquinone, fatty acid composition, and polar lipids.
- DNA G+C content determination and DNA-DNA relatedness studies.
Main Results:
- Strain BS-12M(T) is a Gram-positive, facultatively anaerobic, rod-shaped bacterium.
- Optimal growth occurred at 35 °C, pH 7.0-8.0, and 2.0% NaCl.
- Phylogenetic analysis showed highest 16S rRNA gene similarity (98.6%) to Demequina aestuarii.
- Distinct phenotypic properties, peptidoglycan type (A4β), major menaquinone (MK-9(H4)), fatty acids (anteiso-C15:0, C16:0), and polar lipids (phosphatidylinositol, phosphatidylinositolmannoside) were identified.
- DNA G+C content was 70.7 mol%, with DNA-DNA relatedness values of 15-34% to related species.
Conclusions:
- Strain BS-12M(T) exhibits significant phylogenetic and genetic distinctiveness from known Demequina species.
- The data support the classification of strain BS-12M(T) as a novel species, Demequina activiva sp. nov.
- The proposed type strain is BS-12M(T) (KCTC 29674(T) = NBRC 110675T).
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