Chryseobacterium barbadense sp. nov. Isolated from Pelagic Sargassum Seaweed Waste

A Gram-stain-negative, non-motile and yellowish-orange colored bacterium, designated as Alg-005^T, was isolated from decomposing pelagic Sargassum biomass stranded off the coast of Barbados. The 16S rRNA gene analysis revealed that the strain Alg-005^T closely relates to Chryseobacterium daecheongense DSM 15,235^T (99.1%) and C. defluvii DSM 14,219^T (98.7%). Subsequently, genome-based analysis was performed to assess the evolutionary relatedness of strain Alg-005^T via determination of the overall genomic relatedness indices (OGRI) values, dDDH (digital DNA-DNA hybridization), ANI (average nucleotide identity), orthoANI (orthologous average nucleotide identity) and AAI (average amino acid identity). The dDDH, ANI, orthoANI and AAI values between the genome sequences of the strain Alg-005^T and its closest relative C. daecheongense DSM 15,235^T were recorded as 33.3%, 87.1%, 87.4% and 91.5%, respectively. These OGRI values were well below the recommended cut-off values (dDDH < 70%, ANI < 95-96%, orthoANI < 95-96% and AAI < 95%) for delineation of a novel bacterial species. The unique cellular fatty acids of the strain Alg-005^T compared to C. daecheongense DSM 15,235^T were identified as C14:0, iso-C14:0 3-OH, iso-C16:0, C16:1 ω7c/C16:1 ω6c, iso-C17:1 ω5c, iso-C17:1 ω7c, iso-C17:1 ω12c, C18:0 and C18:1 ω7c. The distinct phenotypic characteristics of the strain Alg-005^T compared to C. daecheongense DSM 15,235^T include, the utilization of D-galactose, L-histidine, α-ketoglutaric acid, L-maleic acid, D-maltose, propionic acid, quinic acid and D-salicin. Therefore, the strain Alg-005^T represents a novel species of genus Chryseobacterium, for which the name Chryseobacterium barbadense sp. nov. is proposed. The type strain is Alg-005^T (= DSM 117339^T = LMG 33495^T).