Aquabacterium terrae sp. nov., isolated from soil

Abstract

A yellow-colored bacterial strain, designated S2^T was isolated from soil in South Korea. Cells of strain S2^T were strictly aerobic, Gram-stain-negative, motile with single polar flagellum, rod-shaped, oxidase and catalase-negative. Growth occurs at 10-37 °C (optimum, 28 °C), pH 5.0-9.0 (optimum, pH 6.5-7.0) and 0-3% NaCl (w/v). Strain S2^T consisted of summed feature 3 (iso-C_15:0 2-OH and/or C_16:1 ω7c), C_16:0 and summed feature 8 (C_18:1 ω7c and/or C_18:1 ω6c) as major fatty acids. The sole respiratory quinone was Q-8. The polar lipid profile consisted of phosphatidylethanolamine and an unidentified lipid. The 16S rRNA gene sequence analysis showed that strain S2^T is phylogenetically closest to Aquabacterium pictum W35^T (98.4% sequence similarity). The genome of strain S2^T was 8,039,486 bp with 56 scaffolds. The genome consisted of 10 putative biosynthetic gene clusters that are responsible for various secondary metabolites. Genomic DNA G + C content of strain S2^T was 69.4%. The average nucleotide identity and in silico DNA-DNA hybridization values between strain S2^T and phylogenetically related taxa were ≤ 77.9 and ≤ 21.4%, and respectively. The results of genotypic and phenotypic data showed that strain S2^T could be distinguished from its phylogenetically related species and represents a novel species in the genus Aquabacterium, for which the name Aquabacterium terrae sp. nov. is proposed. The type strain is S2^T (= KCTC 72741 ^T = NBRC 114609 ^T).

Keywords: Aquabacterium tarrae; Soil; Uncultured species.