Parasediminibacterium schistidii sp. nov., a novel member of the family Chitinophagaceae isolated from a glacier moss ball in the Canadian High Arctic.

An aerobic, Gram-stain-negative bacterium, designated strain NIPR152T, was isolated from a glacier moss ball (glacier mice; Schistidium agassizii) collected from Ellesmere Island in the Canadian High Arctic. Cells were non-motile, rod-shaped, and formed orange-pigmented colonies. The strain grew at 4-30 °C (optimum, 18 °C), at pH 5.5-8.0 (optimum, pH 7.0-7.5), and tolerated up to 1.0% (w/v) NaCl. Strain NIPR152T exhibited psychrotolerant growth and hydrolyzed starch and cellulose, distinguishing it from its closest known relative. Phylogenetic analysis based on 16S rRNA gene sequences placed the strain within the genus Parasediminibacterium (family Chitinophagaceae), with the highest similarity (95.29%) to Parasediminibacterium paludis HME6815ᵀ. Genome-based analyses supported its novelty, with OrthoANIu and in silico DNA-DNA hybridization values of 71.84% and 20.80%, respectively, while genus-level metrics including average amino acid identity (70.9%) and percentage of conserved proteins (52.1%) supported its placement within the genus Parasediminibacterium. Compared with P. paludis HME6815T, strain NIPR152T possessed a larger genome and showed differences in functional gene composition, including relatively higher representation of selected nitrogen-related and hemicellulose-associated functions, whereas P. paludis showed higher densities of several stress- and photoprotection-related genes. The major respiratory quinone was menaquinone-7 (MK-7), and the dominant fatty acids were summed feature 3 (C16:1ω7c and/or C16:1ω6c), iso-C15:0, and C15:1ω6c. The genomic G + C content was 40.38%. Phenotypic, chemotaxonomic, and genotypic characteristics support the classification of strain NIPR152T as representing a novel species of the genus Parasediminibacterium, for which the name Parasediminibacterium schistidii sp. nov. is proposed. The type strain is NIPR152T (= JCM 36343T = KCTC 102165T).