Two bacterial strains, designated KV-962 T and KV-963, were isolated from soil collected from a field in Japan. Cells of both strains were Gram-staining-positive, non-spore-forming, short rodshaped and motile. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these strains were related to Conexibacter woesei DSM 14684 T , with a similarity value of 98.6 %. These strains possessed MK-7 (H 4 ) as the sole menaquinone and contained C 18 : 1 v9c, C 17 : 1 v6c and iso-C 16 : 0 as the major fatty acids. On the basis of genotypic and phenotypic characteristics, strain KV-962 T and KV-963 were indicated as a novel species of the genus Conexibacter, for which the name Conexibacter arvalis sp. nov. is proposed. The type strain is KV-962 T (5DSM 23288 T 5NBRC 106558 T ). Kageyama et al. (2005Kageyama et al. ( , 2007Kageyama et al. ( , 2008) isolated many strains using agar media supplemented with oxidant scavengers and proposed several new genera. Patulibacter minatonensis KV-614 T , belonging to the order Solirubrobacterales (Reddy & Garcia-Pichel, 2009), is a novel species of genus Patulibacter, strains of which were also isolated using medium supplemented with superoxide dismutase (Takahashi et al., 2006). The order Solirubrobacterales is positioned within a deeply branching lineage of the class Actinobacteria and contains only three genera and five species. In the present study, we attempted to isolate new strains related to these five species; however, as all species in this order grow slowly, isolation can prove difficult using standard methods and media. With this in mind, the present study extended to the use of poor medium, on which most bacteria grow slowly and where oxidative stress is weak (Takahashi et al., 2003), allowing the isolation of two novel strains, designated KV-962 T and KV-963. Phylogenetic and chemotaxonomic characteristics indicated that these strains belong to the genus Conexibacter (Monciardini et al., 2003). In this study, we describe the taxonomic position of strains KV-962 T and KV-963, which represent the second novel species of genus Conexibacter.Strains KV-962 T and KV-963 were isolated from a soil sample collected from a field in Saitama prefecture, Japan, by incubation at 27 u C for 21 days on 1/5 strength nutrient agar (1/5 NA; Difco) with 0.002 % benlate (DuPont). The cultural characteristics of the two strains were examined after cultivation at 27 u C for 14 days on 1/5 NA, nutrient agar, ISP medium 5 (DAIGO; Nihon Pharmaceutical), brain heart infusion agar (BHI; Difco), 1/5 strength BHI agar, R2A agar (Difco), 1/5 strength R2A agar, tryptic soy agar (TSA; Difco), Todd-Hewitt agar (THA; Difco), 1/5 strength THA and GPM agar (1 % glucose, 0.5 % peptone, 0.5 % meat extract, 0.3 % NaCl, 1.2 % agar; pH 7). The motility of cells, incubated at 27 u C for 21 days on 1/5 NA, was determined by using light microscopy and morphological characteristics of the strains were determined using a transmission electron microscope (JEM-1200EXII; JEOL) after staining with 1 % uranyl a...