Flavobacterium humi sp. nov., a flexirubin-type pigment producing bacterium, isolated from soil

Abstract

A yellow pigmented, Gram-stain-negative, strictly aerobic, rod-shaped, motile by means of gliding, catalase and oxidase positive bacterium, designated strain DS2-A(T), was isolated from soil. Growth was observed at 4-32 degrees C (optimum, 28 degrees C), pH 6-9 (optimum, 7.0), and with 0-0.25% (w/v) NaCl (optimum, 0%). Phylogenetic analysis of 16S rRNA gene sequence revealed that strain DS2-A(T) belonged to the genus Flavobacterium and was most closely related to Flavobacterium aquatile LMG 4008(T) (96.4%), Flavobacterium terrae DSM 18829(T) (95.6%), Flavobacterium vireti THG-SM1(T) (95.5%), Flavobacterium inkyongense IMCC27201(T) (95.4%), Flavobacterium brevivitae TTM-43(T) (95.2%), and Flavobacterium cucumis DSM 18830(T) (95.2%). Strain DS2-A(T) produces flexirubin-type pigments. The major fatty acids were iso-C-15:0, iso-C-17:0 3-OH, and iso-C-15:0 3-OH. The major respiratory quinone was identified as menaquinone-6. The major polar lipid was found to be phosphatidylethanolamine. The average nucleotide identity values between strain DS2-A(T) and selected taxa, F. aquatile LMG 4008(T), F. terrae DSM 18829(T), and F. cucumis DSM 18830(T), were 72, 72.7, and 71.6%, respectively. The draft genome of strain DS2-A(T) has a number of 14 contigs, scaffold N50 of 476,310 bp and a total size of 3,563,867 bp. Additionally, strain DS2-A(T) contains 3,127 of gene, 41 of tRNA, 6 of rRNA, and 3 of ncRNA. The DNA G + C content of stain DS2-A(T) was 40.7 mol%. Based on phylogenetic and phenotypic analyses, strain DS2-A(T) is considered as a novel species of the genus Flavobacterium, for which the name Flavobacterium humi sp. nov., (type strain DS2-A(T) = KACC 19715(T) = JCM 32786(T)) has been proposed.