Leucobacter humi sp. nov., Isolated from Forest Soil.

Abstract

A novel bacterial strain, designated Re6(T), was isolated from forest soil collected in Campbell University, North Carolina. The cells are aerobic, Gram-positive, non-motile, and rod shaped. Growth occurred at 4-42°C (optimum, 25°C), pH 6-9 (optimum, pH 6), and in 0-3% NaCl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain Re6(T) belonged to the genus Leucobacter and showed the highest 16S rRNA gene sequence similarities with Leucobacter iarius JCM 14736(T) (98.3%), Leucobacter luti JCM 14920(T) (97.9%), Leucobacter komagatae JCM 9414(T) (97.8%), and Leucobacter denitrificans KACC 14055(T) (97.7%). Strain Re6(T) contained anteiso-C15:0 (45.2%), iso-C16:0 (17.1%), and anteiso-C17:0 (32.6%) as the major cellular fatty acids; MK-11 as the major respiratory quinone; L-diaminobutyric acid as the diagnostic diamine acid in cell wall peptidoglycan; and diphosphatidylglycerol and phosphatidylglycerol as the main polar lipids. The DNA G+C content of the strain Re6(T) was 66.6mol%. DNA-DNA hybridization results showed similarity values less than 50% for DNA samples from the most closely related type strains of L. iarius, L. luti, and L. komagatae. On the basis of the data from the polyphasic analysis, strain Re6(T) is considered to be a representative novel species in the genus Leucobacter, for which the name Leucobacter humi sp. nov. is proposed. The type strain is Re6(T) (KEMC 7301-006(T)=JCM 18638(T)).