Abstract
Strain LB-N7(T), a novel Gram-negative, orange, translucent, gliding, rod-shaped bacterium, was isolated from water samples collected from an open system of Atlantic salmon (Salmo salar) smolts in a fish farm in Chile during a flavobacterial infection outbreak in 2015. Phylogenetic analysis based on 16S rRNA sequences (1337 bp) revealed that strain LB-N7(T) belongs to the genus Flavobacterium and is closely related to the type strains Flavobacterium ardleyense A2-1(T) (98.8 %) and Flavobacterium cucumis R2A45-3(T) (96.75 %). The genome size of strain LB-N7(T) was 2.93 Mb with a DNA G+C content 32.6 mol%. Genome comparisons grouped strain LB-N7(T) with Flavobacterium cheniae NJ-26(T), Flavobacterium odoriferum HXWNR29(T), Flavobacterium lacisediminis TH16-21(T) and Flavobacterium celericrescens TWA-26(T). The calculated digital DNA-DNA hybridization values between strain LB-N7(T) and the closest related Flavobacterium strains were 23.3 % and the average nucleotide identity values ranged from 71.52 to 79.39 %. Menaquinone MK-6 was the predominant respiratory quinone, followed by MK-7. The major fatty acids were iso-C(15 : 0) and anteiso-C(15 : 0). The primary polar lipids detected included nine unidentified lipids, two amounts of aminopospholipid and phospholipids, and a smaller amount of aminolipid. Phenotypic, genomic, and chemotaxonomic data suggest that strain LB-N7(T) (=CECT 30406(T)=RGM 3221(T)) represents as a novel bacterial species, for which the name Flavobacterium psychraquaticum sp. nov. is proposed.