Proteus cibarius sp. nov., a swarming bacterium from Jeotgal, a traditional Korean fermented seafood, and emended description of the genus Proteus.

A novel Proteus-like, Gram-stain-negative, facultatively anaerobic, rod-shaped bacterium, designated strain JS9T, was isolated from Korean fermented seafood, Jeotgal. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain JS9T belonged to the genus Proteus in the family Enterobacteriaceae. The highest 16S rRNA gene sequence similarity of strain JS9T was to Proteus vulgaris KCTC 2579T (98.98 %) and the genomic DNA G+C content is 39.0 mol%. DNA-DNA hybridization values were measured and strain JS9T showed <20.8 % genomic relatedness with closely-related members of the genus Proteus. The isolate showed bacterial motility and swarming activity similar to those of pathogenic Proteus mirabilis but distinct from those of other species of the genus Proteus. The isolate grows optimally at 30 °C, at pH 7, and in the presence of 2 % (w/v) NaCl. The main respiratory quinones are ubiquinone Q-8 and Q-10, and the major cellular fatty acids are C16 : 0, summed feature 3 and summed feature 8. The polar lipids comprise phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, an unidentified amino lipid, two unidentified amino-phospholipids, and three unidentified lipids. Based on phylogenetic, phenotypic, chemotaxonomic and genotypic analyses, strain JS9T represents a novel species of the genus Proteus, for which the name Proteus cibarius sp. nov. is proposed. The type strain is JS9T (=KACC 18404T=JCM 30699T). An emended description of the genus Proteus is also provided.