Affiliation:
1. Agricultural Microbiology Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju-gun, Jeollabuk-do 55365, Republic of Korea
Abstract
Strain RHs26T is an aerobic, Gram-stain-negative, non-flagellated and rod- or filamentous-shaped (1.0–1.1×2.3–50 µm) bacterium that was isolated from dried rice husk. It was positive for oxidase and catalase, hydrolysed starch and Tween 80, and weakly hydrolysed CM-cellulose. The strain grew at temperatures between 10 and 37 °C (optimum, 28 °C), in 0–1 % NaCl (optimum, 0 %) and at pH 6.0–9.0 (optimum, pH 7.0–8.0). The predominant membrane fatty acids were summed feature 3 (C16 : 1
ω7c and/or C16 : 1
ω6c), C16 : 1
ω5c, iso-C15 : 0 and iso-C17 : 0 3-OH. The major polar lipids were phosphatidylethanolamine, an unidentified aminolipid, two unidentified aminophospholipids and two unidentified lipids. The predominant quinone was menaquinone MK-7. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain RHs26T belongs to the genus
Spirosoma
, presenting the highest sequence similarity to
Spirosoma agri
S7-3-3T (95.8 %). The genomic DNA G+C content of strain RHs26T was 49.5 %. Strain RHs26T showed the highest orthologous average nucleotide identity (OrthoANI) and digital DNA–DNA hybridization (dDDH) values of 76.4 % and 20.0 % with
S. agri
KCTC 52727T while sharing OrthoANI and dDDH values of 74.6 % and 19.2 % with
Spirosoma terrae
KCTC 52035T, the closest relative in the phylogenomic tree. Based on the results of a polyphasic taxonomic study, strain RHs26T represents a novel species in the genus
Spirosoma
, for which the name Spirosoma oryzicola sp. nov. is proposed. The type strain is RHs26T (=JCM 35224T=KACC 17318T).
Subject
General Medicine,Ecology, Evolution, Behavior and Systematics,Microbiology