Rudanella lutea gen. nov., sp. nov., isolated from an air sample in Korea.

An orange-coloured bacterial strain, designated 5715S-11(T), was isolated from an air sample in Suwon, Republic of Korea. The strain was strictly aerobic, Gram-negative, non-spore-forming, non-flagellated and rod-shaped, frequently forming filaments. Growth of the strain was observed at 4-40 degrees C (optimum, 30 degrees C), pH 6.0-8.0 (optimum, pH 7.0) and 0-2 % (w/v) NaCl. Phylogenetically, strain 5715S-11(T) was shown to be a member of the family Spirosomaceae within the phylum Bacteroidetes. Its closest relatives were Spirosoma linguale LMG 10896(T) (87.9 % 16S rRNA gene sequence similarity) and Larkinella insperata LMG 22510(T) (86.2 % 16S rRNA gene sequence similarity). Predominant cellular fatty acids were summed feature 3 (C(16 : 1)omega7c and/or iso-C(15 : 0) 2-OH), C(16 : 1)omega5c and iso-C(15 : 0). Major polar lipids were phosphatidylethanolamine and unknown aminolipids and polar lipids. On the basis of the evidence from this polyphasic study, strain 5715S-11(T) is considered to represent a novel species of a new genus, for which the name Rudanella lutea gen. nov., sp. nov. is proposed. The type strain of Rudanella lutea is 5715S-11(T) (=KACC 12603(T) =DSM 19387(T)).