Sphingomonas rubra sp. nov., isolated from bioreactor wastewater

Abstract

A Gram-reaction-negative, rod-shaped, motile, neutrophilic bacterium, designated strain BH3(T), was isolated from wastewater of a sequential batch reactor treating wastewater taken from a leather plant. The isolate grew in 0-8 % (w/v) NaCl, at pH 6-9 and at 4-45 °C. Chemotaxonomic analysis showed that strain BH3(T) had characteristics typical of members of the genus Sphingomonas, such as the presence of sphingolipids, Q-10 and 2-hydroxymyristic acid and the absence of 3-hydroxy fatty acids. The presence of C(18 : 1)ω7c (39.2 %) and C(16 : 0) (11.2 %) as major fatty acids, C(14 : 0) 2-OH (20.6 %) as the major 2-hydroxy fatty acid and homospermidine as the major polyamine indicated that strain BH3(T) belonged to the genus Sphingomonas sensu stricto. The genomic DNA G+C content of strain BH3(T) was 65.6 mol%. 16S rRNA gene sequence similarities between the isolate and closely related members of the genus Sphingomonas sensu stricto ranged from 92.6 to 97.3 %, the highest sequence similarities being to Sphingomonas melonis DSM 14444(T) (97.3 %) and Sphingomonas aquatilis DSM 15581(T) (97.3 %). Based on its phenotypic characteristics and the results of DNA-DNA hybridization studies and 16S rRNA gene sequence comparisons, strain BH3(T) represents a novel species of the genus Sphingomonas sensu stricto, for which the name Sphingomonas rubra sp. nov. is proposed. The type strain is BH3(T) ( = CGMCC 1.9113(T) = JCM 16230(T)).