Niabella agricola sp. nov., isolated from paddy soil

A polyphasic taxonomic approach was used to characterize a Gram-stain-negative, orange-coloured bacterium (designated strain CC-SYL272^T) isolated from paddy soil. Cells were observed to be strictly aerobic, non-motile and non-spore-forming rods, exhibiting positive catalase and oxidase. Strain CC-SYL272^T was found to grow optimally at 20-40 °C, pH 6.0-8.0 and NaCl 0-2 % (w/v). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CC-SYL272^T belongs to the genus Niabella, family Chitinophagaceae, and is most closely related to Niabella pedocola (97.8 %) followed by Niabella drilacis (97.2 %) and established a distinct taxonomic lineage associated with these species. The highest orthologous average nucleotide identity (OrthoANI) values were recorded for strain CC-SYL272^T versus Niabella species (69.1-83.5 %, n=8). The mean digital DNA-DNA hybridization (dDDH) value obtained for strain CC-SYL272^T against N. pedocola was 27.3 %. The polar lipid profile consisted of phosphatidylethanolamine and five unidentified lipids. The major polyamines were putrescine and sym-homospermidine. The dominating cellular fatty acids (>5 %) included iso-C_15 : 0, iso-C_15 : 1 G, iso-C_17 : 0 3OH and C_16 : 1  ω6c/C_16 : 1  ω7c. The draft genome (6.25 Mb) of strain CC-SYL272^T spanned three contigs having 47.1 mol% DNA G+C content, 5087 protein-encoding genes, 10 rRNA genes and 44 tRNA genes. The genome harboured genes involved in the depolymerization of both animal and plant polysaccharides. Based on its distinct phylogenetic, phenotypic and chemotaxonomic traits together with results of comparative 16S rRNA gene sequence, OrthoANI, dDDH and the phylogenomic placement, strain CC-SYL272^T is considered to represent a novel species of the genus Niabella, affiliated to the family Chitinophagaceae, for which the name Niabella agricola sp. nov. is proposed. The type strain is CC-SYL272^T (=BCRC 81319^T=JCM 34758^T).