Ideonella livida sp. Nov., isolated from a freshwater lake

Abstract

A novel bacterial strain, designated TBM-1T, isolated from a freshwater lake in Taiwan, was characterized using a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain TBM-1T formed a phylogenetic lineage in the genus Ideonella. Analysis of 16S rRNA gene sequences showed that strain TBM-1T was most closely related to Ideonella dechloratans CCUG 30898T with 98.4 % sequence similarity. The average nucleotide identity, average amino acid identity and digital DNA–DNA hybridization values between strain TBM-1T and closely related strains of the genus Ideonella were 74.4–77.5 %, 69.7–75.4 % and 19.8–21.8 %, respectively, supporting that strain TBM-1T represents a novel species of the genus Ideonella. Cells were Gram-stain-negative, motile by means of a single polar flagellum, rod-shaped and formed blue colonies. Optimal growth occurred at 30 °C, pH 6 and 0 % NaCl. The predominant fatty acids of strain TBM-1T were summed feature 3 (C16: 1 ω7c and/or C16: 1 ω6c), C18: 1 ω7c and C16: 0. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, two uncharacterized aminophospho-lipids and two uncharacterized phospholipids. The main polyamine was putrescine. The major isoprenoid quinone was Q-8. The estimated genome size was 5.26 Mb, with an average G+C content of 70.0 mol%. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain TBM-1T should be classified in a novel species of the genus Ideonella, for which the name Ideonella livida sp. nov. is proposed. The type strain is TBM-1T (=BCRC 81199T =LMG 31339T).