Sphingobium scionense sp. nov., an aromatic hydrocarbon-degrading bacterium isolated from contaminated sawmill soil

Abstract

This study characterized strain WP01T, a Gram-staining-negative, rod-shaped, aerobic bacterium isolated from a polycyclic aromatic hydrocarbon-contaminated soil in New Zealand. Strain WP01T shared many characteristics of the genus Sphingobium: the predominant respiratory quinone (89 %) was ubiquinone with ten isoprene units (Q-10); the major fatty acids were C18 : 1 ω7c, C16 : 1 ω7c, C16 : 0 and C14 : 0 2-OH; spermidine was the major polyamine; the DNA G+C content was 63.8 mol%; and the Sphingobium-specific 16S rRNA signatures were conserved. A point of difference from other species of the genus Sphingobium was that strain WP01T reduced nitrate to nitrite. The polar lipid pattern consisted of the predominant compounds diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and sphingoglycolipids. 16S rRNA gene sequence analysis showed that, amongst the recognized species of the genus Sphingobium, strain WP01T was most similar to Sphingobium yanoikuyae GIFU 9882T and Sphingobium amiense YTT (>97 % 16S rRNA gene sequence similarities). The low DNA–DNA relatedness values between strain WP01T and S. yanoikuyae GIFU 9882T (46.6 %) and S. amiense DSM 16289T (25.6 %) indicated no relatedness at the species level. On the basis of these characteristics, it is concluded that strain WP01T should be considered as representing a novel species within the genus Sphingobium, for which the name Sphingobium scionense sp. nov. is proposed. The type strain is WP01T (=DSM 19371T=ICMP 13533T).