Brevundimonas humi sp. nov., an alphaproteobacterium isolated from forest soil.

ABSTRACT

During a study of bacterial diversity of soil, a novel strain, CA-15T, was isolated from Kyonggi University forest soil. Cells were aerobic, Gram-stain-negative, motile, non-spore-forming, rod-shaped, oxidase-positive and catalase- negative. Tyrosine was not oxidized but produced red pigmentation on an agar palte. Strain CA-15T hydrolysed Tween 60 and DNA. It grew at 15-35 °C (optimum, 25-30 °C), pH 6.0-10.0 (optimum, 7.0-9.0) and at 1.5 % (w/v) NaCl concentration. Phylogenetic analysis based on its 16S rRNA gene sequence indicated that strain CA-15T formed a lineage within the family Caulobacteraceae of the class Alphaproteobacteria that was distinct from various species of the genus Brevundimonas. Brevundimonas bullata DSM 7126T was the closest member of strain CA-15T on the basis of 16S rRNA gene sequence similarity (98.48 %). Q-10 was only an isoprenoid quinone detected for strain CA-15T. The major polar lipids were 1,2-di-O-acyl-3-O-[d-glucopyranosyl-(1→4)-αd-glucopyranuronosyl]glycerol, 1,2-di-O-acyl-3-O-[αd-glucopyranosyl]-sn-glycerol, 1,2-di-O-acyl-3-O-αd-glucopyranuronosylglycerol, 1,2-diacyl-3-O-[6'-phosphatidyl-αd-glucopyranosyl]glycerol and phosphatidylglycerol. The major cellular fatty acids were summed feature 8 (C18  1ω7c and/or C18  1ω6c), C16  0, C18  1ω7c 11-methyl and C17  1ω8c. The DNA G+C content of strain CA-15T was 63.6 mol%. The polyphasic characterization indicated that strain CA-15T represents a novel species in the genus Brevundimonas, for which the name Brevundimonas humi sp. nov. is proposed. The type strain of Brevundimonas humi is CA-15T (=KEMB 9005-528T=KACC 19106T=NBRC 112677T).