Flavobacterium pygoscelis sp. nov., isolated from a chinstrap penguin chick (Pygoscelis antarcticus)

Abstract

Strain I-SCBP12n^T, a novel Gram-stain-negative, aerobic, non-spore-forming, motile-by-gliding and rod-shaped bacterium, was isolated from a chinstrap penguin chick (Pygoscelis antarcticus) during a 2015 expedition to the Chilean Antarctic territory. Phylogenetic analysis based on 16S rRNA gene sequencing confirmed that strain I-SCBP12n^T belonged to the genus Flavobacterium, being closely related to strains Flavobacterium chryseum P3160^T (98.52 %), Flavobacterium hercynium WB 4.2-33^T (98.47 %) and Flavobacterium chilense LM-19-Fp^T (98.47 %). The genome size of strain I-SCBP12n^T was 3.69 Mb with DNA G+C content 31.95 mol%. Genomic comparisons of strain I-SCBP12n^T with type species in the genus Flavobacterium were performed, with obtained average values near 75.17 and 84.33 % for the blast and MUMer analyses of average nucleotide identity, respectively, and 0.86 for the tetranucleotides frequency analysis. These values are far from the accepted species cut-off values. Strain I-SCBP12n^T contained MK-6 as the predominant menaquinone and the major polar lipids were aminophospholipid, an unidentified aminolipid and unidentified lipids. The predominant fatty acids (> 5 %) were iso-C_{14 : 0}, iso-C_{15 : 0}, anteiso-C_{15 : 0}, iso-C_{16 : 0}, iso-C_{16 : 1}, iso-C_{16 : 0} 3-OH, C_{15 : 1} ω6c and summed feature 3 (C_{16 : 1} ω7c/C_{16 : 1} ω6c). Phenotypic, chemotaxonomic and genomic data supported the assignment of strain I-SCBP12n^T (=CECT 30404^T=RGM 3223^T) to a novel species of Flavobacterium, for which the name Flavobacterium pygoscelis sp. nov.is proposed.

Keywords: Antarctica; Flavobacterium; penguin.