Iodobacter limnosediminis sp nov., isolated from Arctic lake sediment

A Gram-reaction-negative, motile, non-violet-pigmented, rod-shaped bacterial strain, designated E1(T), was isolated from Arctic lake sediment. Growth occurred at 4 degrees C-28 degrees C (optimum, 18 degrees C), at pH 4-11(optimum, 9-10) and in the presence of 0-1% (w/v) NaCl. The taxonomic position of E1(T) was analysed using a polyphasic approach. Strain E1(T) exhibited 16S rRNA gene sequence similarity value of 98.1% with respect to the type strain of Iodobacter fluviatilis, but no more than 93% with the type strains of other recognized species. A further DNA-DNA hybridization experiment was conducted, which demonstrated unambiguously that strain E1(T) was distinct from I. fluviatilis ATCC 33051(T) (51.3% relatedness). The DNA G+C content of strain E1(T) was 52.3 mol%. Chemotaxonomic data [Q-8 as the monospecific respiratory quinone and summed feature 3 (C-16:1 omega 7c and/or C-16:1 omega 6c, 56.1%) and C-16:0 (18.8%) as the major cellular fatty acids] supported the affiliation of strain E1(T) to the genus Iodobacter. However, the results of physiological and biochemical tests allowed phenotypic differentiation of strain E1(T) from I. fluviatilis ATCC 33051(T). On the basis of phenotypic and genotypic properties, strain E1(T) represents a novel species of genus Iodobacter, for which the name Iodobacter limnosediminis sp. nov. is proposed. The type strain is E1(T) (=CCTCC AB 2010224(T)=NRRL B-59456(T)).