Runella defluvii sp. nov., isolated from a domestic wastewater treatment plant

A long, Gram-negative, rod-shaped bacterium, designated strain EMB13T, was isolated from a wastewater treatment plant in Korea. The isolate was strictly aerobic and non-motile. The strain grew optimally at 30-35 degrees C and pH 7.5-8.0, and the predominant fatty acids were iso-C15:0, summed feature 3 (C16:1omega7c and/or iso-C15:0 2-OH), C16:1omega5c and iso-C17:0 3-OH. The strain contained a large amount of phosphatidylethanolamine and small amounts of phosphatidylcholine and an unknown phospholipid as the polar lipids. The G+C content of the genomic DNA was 40.1 mol% and the major isoprenoid quinone was menaquinone-7. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain EMB13T belonged to the genus Runella and was most closely related to Runella limosa EMB111T, with a 16S rRNA gene sequence similarity of 97.1%. DNA-DNA relatedness between strain EMB13T and R. limosa EMB111T was approximately 25%. On the basis of phenotypic, chemotaxonomic and molecular data, it is clear that strain EMB13T represents a novel species within the genus Runella, for which the name Runella defluvii sp. nov. is proposed. The type strain is EMB13T (=KCTC 12614T=DSM 17976T).