Arenimonas oryziterrae sp nov., isolated from a field of rice (Oryza sativa L.) managed under a no-tillage regime, and reclassification of Aspromonas composti as Arenimonas composti comb. nov.

Abstract

The taxonomic position of a novel bacterial strain, YC6267(T) isolated from a field of rice (Oryza sativa L.) managed under a no-tillage regime in Jinju, Korea, was studied using a polyphasic taxonomic approach. Cells of the strain were Gram-stain-negative, rod-shaped and aerobic. It grew at 15-37 degrees C (optimum at 28 degrees C). Growth of the strain occurred between pH 5.0 and 10.0, with an optimum of pH 7.0-8.0. The G + C content of the total DNA was 65.8 mol%. The 16S rRNA gene sequence of the strain was most closely related to species of the genera Arenimonas (95.6-94.4%) and Aspromonas (95.1%), with <95.0% similarity to species of the genus Lysobacter and other genera of the family Xanthomonadaceae. Chemotaxonomic data (major quinone Q-8; major polar lipids phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol; and major fatty acids iso-C-1.5:0, iso-C-14:0, iso-C-16:0, and iso-C-17:1 omega 9C) supported the affiliation of strain YC6267(T) to the genus Arenimonas. Phylogenetic analysis based on 16S rRNA gene sequences and biochemical and physiological characteristics strongly supported the genotypic and phenotypic differentiation of strain YC6267(T) from described species of the genus Arenimonas. Strain YC6267(T), therefore, represents a novel species, for which the name Arenimonas oryziterrae sp. nov. is proposed. The type strain is YC6267(T) (=KCTC 22247(T) =DSM 21050(T)). In addition, the reclassification of Aspromonas composti as Arenimonas composti comb. nov. is proposed (type strain TR7-09(T) =KCTC 12666(T) = DSM 18010(T)). A common line of descent and a number of shared phenotypic traits support this reclassification.