Novosphingobium lentum sp nov., a psychrotolerant bacterium from a polychlorophenol bioremediation process

A polychlorophencil-clegrading strain, designated MT1(T), and three MT1 -like strains, MT101, MT103 and MT104, were isolated from a cold (4-8 degrees C) fluidized-bed process treating chlorophenol-contaminated groundwater in southern Finland. The organisms were Gram-negative, rod-shaped, catalase-positive, non-spore-forming and non-motile. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strains belonged to the alpha-4 subclass of the Proteobacteria and were members of the genus Novosphingobium. The highest 1 EIS rRNA gene sequence similarity observed for these strains was 96 center dot 5 % with the type strains of Novosphingobium hassiacum, Novosphingobium aromaticivorans and Novosphingobium subterraneum. Chemotaxonomic data (major ubiquinone: 0- 10; major polyamine: spermidine; major polar lipids: phosphaticlylethanolamine, phosphaticlylglycerol, cliphosphatidylglycerol, phosphatidylcholine and sphingoglycolipid; major fatty acids: 18:1 omega 7c, 16: 1 omega 7c and 2-OH 14 : 0) as well as the ability to reduce nitrate supported the affiliation of the strains to the genus Novosphingobium. Based on the phylogenetic analysis, whole-cell fatty acid composition as well as biochemical and physiological characteristics, the MT1 -like strains were highly similar and could be separated from all recognized Novosphingobium species. The novel species Novosphingobium lentum sp. nov. is proposed to accommodate strains MT1(T) (= DSM 13663(T) =CCUG 45847(T)), MT101 (= CCUG 45849), MT103 (= CCUG 45850) and MT104 (=CCUG 45851).