Hahella ganghwensis

Hahella gaghwensis is a marine strain of Gram-negative, aerobic, and obligately halophilic bacteria of the gammaproteobacteria.^[3] Unlike its relative, H. chejuensis, H. ganghwensis is obligately halophilic, and both have distinctly different metabolic capabilities and fatty acid content.^[4]

Morphology

Hahella ganghwensis forms a round, smooth, and convex colony with rod-shaped cells that are motile via the propulsion of a unipolar flagellum.^[3] The colony has a cream color, as opposed to the red pigment seen in H. chejuensis and this can be used in situ to differentiate between the two.^[5]

Isolation

Hahella gaghwensis was first characterized from isolates obtained from the Ganghwen Island off of the coast of South Korea.^[3] It was discovered in 2005 while South Korean researchers were conducting studies of diversity for the known species, H. chejuensis. They determined through 16S rRNA sequencing that a strain, FR1050, was distinct enough from model H. chejuensis rRNA to warrant description as a separate species, and further research showed various biochemical and physiological differences

Metabolism

Notable for the aerobic microbe is the ability of H. ganghwensis to produce an overabundance of extracellular polysaccharides.^[3] Though it is incapable of nitrate reduction, it does favor N-acetylglucosamine for growth.^[3] It does not grow in the presence of nitrate, adipate, gluconate, or caprate^[3]

Phylogeny

Based on 16S rRNA sequencing, the closest relatives were H. chejuensis strain KCTC 2396T (94.7%), Zooshikella ganghwensis strain JC2044T (90.1%) and Microbulbifer hydrolyticus strain DSM 11525T (90.7%).^[6] It is in the gamma proteobacteria, but has no known industrial or human health affects, and more research will be required in order to determine the niche that the bacterial strain occupies.^[7]

References