Arcicella aurantiaca sp. nov., isolated from stream water.

A bacterial strain designated TNR-18(T) was isolated from stream water in southern Taiwan and characterized using a polyphasic taxonomic approach. Cells of strain TNR-18(T) were Gram-stain-negative, strictly aerobic, non-motile and vibrioid, and the strain formed orange colonies. Growth occurred at 10-30°C, with 0-0.2 % NaCl and at pH6.0-10.0. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain TNR-18(T) belonged to the genus Arcicella; its closest neighbours were Arcicella rosea TW5(T) and Arcicella aquatica NO-502(T), with respective sequence similarities of 97.9 and 97.8 %. Predominant cellular fatty acids (>10 %) were summed feature 3 (C(16 : 1)ω7c/C(16 : 1)ω6c; 37.7 %), C(16 : 1)ω5c (13.0 %) and iso-C(15 : 0) (11.1 %). The major respiratory quinone was MK-7. The polar lipid profile contained phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and several uncharacterized polar lipids. The DNA G+C content was 39.9 mol%. On the basis of the phylogenetic and phenotypic data, strain TNR-18(T) should be classified as representing a novel species, for which the name Arcicella aurantiaca sp. nov. is proposed. The type strain is TNR-18(T) (=LMG 25207(T) =BCRC 17969(T)).