Maribacter halichondris sp. nov., isolated from the marine sponge Halichondria panicea

A new member of the family Flavobacteriaceae (termed Hal144T) was isolated from the marine breadcrumb sponge Halichondria panicea. Sponge material was collected in 2018 at Schilksee which is located in the Kiel Fjord (Baltic Sea, Germany). Phylogenetic analysis of the full-length Hal144T 16S rRNA gene sequence revealed similarities from 94.3% - 96.6% to the nearest type strains of the genus Maribacter. The phylogenetic tree depicted a cluster of strain Hal144T with its closest relatives Maribacter aestuarii GY20T (96.6%) and Maribacter thermophilus HT7-2T (96.3%). Genome comparisons of strain Hal144T with Maribacter spp. type strains exhibited average nucleotide identities in the range of 75% - 76% and digital DNA-DNA hybridization values in the range of 13.1% - 13.4%. Strain Hal144T was determined to be Gram-negative, mesophilic, strictly aerobic, flexirubin positive, resistant to aminoglycoside antibiotics, and able to utilize N-acetyl-β-D-glucosamine. Optimal growth occurred at 25 - 30 °C, within a salinity range of 2 - 6% sea salt, and a pH range between 5 - 8. The major fatty acids identified were C17:0 3-OH, iso-C15:0, and iso-C15:1 G. The DNA G+C content of strain Hal144T was 41.4 mol%. Based on the polyphasic approach, strain Hal144T represents a novel species of the genus Maribacter, and we propose the name Maribacter halichondris sp. nov. The type strain is Hal144T (= DSM 114563T = LMG 32744T). ### Competing Interest Statement The authors have declared no competing interest.