Oryzobacter faecalis sp. nov., an Antibiotics-Resistant Actinobacterium of the Family Intrasporangiaceae Isolated from Pig Faeces.

Abstract

A Gram-stain-positive, aerobic, rod-shaped, and non-motile bacterium, designated strain R7^T, was isolated from pig faeces. Strain R7^T grew at 15-37 °C (optimum 30 °C), pH 6-8 (optimum pH 7), and salinity of 0-5.0% (w/v; optimum 1.0%). Strain R7^T was resistant to cefradine, ampicillin, gentamicin, and spectinomycin. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain R7^T belonged to genus Oryzobacter, and showed 98.9% similarity with Oryzobacter terrae PSGM2-16^T. The average nucleotide identity and digital DNA-DNA hybridization values between strain R7^T and O. terrae PSGM2-16^T were 84.5% and 27.6%, respectively. The predominant fatty acids of strain R7^T were iso-C_16:0, C_17:1ω8c, iso-C_14:0, C_17:0, and iso-C_15:0. The predominant ubiquinone was MK-8(H₄). The major polar lipids of strain R7^T were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol, aminophosphoglycolipid, one unidentified phospholipid, and two unidentified polar lipids. The diagnostic diamino acid of the cell-wall peptidoglycan was meso-diaminopimelic acid. Based on the phenotypic, genotypic and phylogenetic evidence, strain R7^T represents a novel species in the genus Oryzobacter, for which the name Oryzobacter faecalis sp. nov. is proposed. The type strain is R7^T (=GDMCC 1.4961^T = KCTC 59403^T = KACC 23902^T).