Abstract

Strain T-12T, an orange, Gram-stain-negative, non-motile, rod-shaped strain, was isolated in November 2013 from water samples collected from an Atlantic salmon (Salmo salar) fry culturing system at a fish farm in Chile. Phylogenetic analysis based on 16S rRNA sequences (1394 bp) revealed that strain T-12T belonged to the genus Flavobacterium, showing close relationships to Flavobacterium bernardetii F-372T (99.48%) and Flavobacterium terrigena DS-20T (98.50%). The genome size of strain T-12T was 3.28 Mb, with a G+C content of 31.1mol%. Genome comparisons aligned strain T-12T with Flavobacterium bernardetii F-372T (GCA_011305415) and Flavobacterium terrigena DSM 17934T (GCA_900108955). The highest digital DNA–DNA hybridization (dDDH) values were 42.6% with F. bernardetii F-372T (GCA_011305415) and 33.9% with F. terrigena DSM 17934T (GCA_900108955). Pairwise average nucleotide identity (ANI) calculations were below the species cutoff, with the best results with F. bernardetii F-372T being: ANIb, 90.33%; ANIm, 91.85%; and TETRA, 0.997%. These dDDH and ANI results confirm that strain T-12T represents a new species. The major fatty acids were iso-C15:0 and C15:1 ?6?. Detected polar lipids included phospholipids (n=2), aminophospholipid (n=1), aminolipid (n=1) and unidentified lipids (n=2). The predominant respiratory quinone was menaquinone MK7 (80%) followed by MK-6 (20%). Phenotypic, chemotaxonomic, and genomic data support the classification of strain T-12T (=CECT 30410T=RGM 3222T) as representing a novel species of Flavobacterium, for which the name Flavobacterium facile sp. nov. is proposed. © 2024 The Authors.