Flavobacterium solisilvae sp. nov. and Flavobacterium silvaticum sp. nov., isolated from forest soil

Abstract

Two Gram-stain-negative, yellow-pigmented and strictly aerobic bacteria, designated strains SE-s27^T and SE-s28^T, were isolated from forest soil. Both strains were non-motile rods that were catalase-positive and oxidase-negative and grew optimally at 25-30 °C, pH 8.0 and with 0 % (w/v) NaCl. Strain SE-s28^T produced flexirubin-type pigments, but strain SE-s27^T did not produce them. Both strains contained menaquinone-6 as the sole respiratory quinone and phosphatidylethanolamine as a major polar lipid. As the major cellular fatty acids (>10 %), SE-s27^T contained iso-C_{15 : 1} and iso-C_{15 : 1}G, whereas SE-s28^T contained iso-C_{15 : 0} and summed feature 3 comprising C_{16 : 1}ω7c and/or C_{16 : 1}ω6c and/or iso-C_{15 : 0} 2-OH. The DNA G+C contents of strains SE-s27^T and SE-s28^T were 33.1 and 44.3 mol%, respectively. The results of phylogenetic analysis based on 16S rRNA gene sequences revealed that SE-s27^T and SE-s28^T formed respective distinct phylogenetic lineages within the genus Flavobacterium. Strains SE-s27^T and SE-s28^T were most closely related to Flavobacterium macrobrachii an-8^T and Flavobacterium piscinae ICH-30^T with 98.0 and 94.5 % 16S rRNA gene sequence similarities, respectively. In conclusion, strains SE-s27^T and SE-s28^T represent novel species of the genus Flavobacterium, for which the names Flavobacterium solisilvae sp. nov. and Flavobacterium silvaticum sp. nov. are proposed. The type strains of F. solisilvae and F. silvaticum are SE-s27^T (=KACC 18802^T=JCM 31544^T) and SE-s28^T (=KACC 18803^T=JCM 31545^T), respectively.

Keywords: Flavobacterium silvaticum; Flavobacterium solisilvae; forest soil; new taxa; taxonomy.