Phaeobacter cretensis sp. nov. and Phaeobacter bryozoorum sp. nov., isolated from seawater from off the coast of Crete and from Roskilde Fjord in Denmark

Two Gram-negative, motile, rod-shaped bacteria, designated as C3_T13_0 T and A36a-5a T , were isolated from marine environments collected off the coast of Crete, Greece, and from a biofilm in Jyllinge Harbor in Roskilde Fjord, Denmark, respectively. 16S rRNA gene phylogeny revealed that the two strains belong to the genus Phaeobacter . The major cellular fatty acids (>5%) were C 18 : 1 ω 7 c for strain A36a-5a T and C 18 : 1 ω 7 c , C 18 : 2 ω 7,13 and C 16 : 0 for strain C3_T13_0 T . The major respiratory quinone was ubiquinone-10, and the predominant polar lipids were phosphatidylcholine, phosphatidylglycerol, and phosphatidylethanolamine for both strains. C3_T13_0 T and A36a-5a T both produce the antimicrobial compound tropodithietic acid. The C3_T13_0 T strain grows at temperatures between 8 and 37 °C with an optimum of 25 °C, whereas A36a-5a T grows between 5 and 37 °C with an optimum of 30 °C. The salinity range for growth was 2–9 % NaCl (w/v) for C3_T13_0 T with an optimum of 3–4% and 0–10% NaCl (w/v) for A36a-5a T with an optimum of 2–6%. The genomes of the two strains shared an average nucleotide identity (ANI) of 84% and had lower than 87% ANI when compared with genomes of Phaeobacter spp. type strains. The genome of C3_T13_0 T was 4,432,895 bp with a G+C content of 55.96 mol%, and the genome of A36a-5a T was 4,050,005 bp with a G+C content of 61.37 mol%. Based on the phylogenetic and phenotypic analyses presented here, the two isolates C3_T13_0 T (=DSM 118664 T =LMG 33738 T ) and A36a-5a T (=DSM 118663 T =LMG 33737 T ) are considered to represent two novel species belonging to the genus Phaeobacter , for which the names Phaeobacter cretensis sp. nov. and Phaeobacter bryozoorum sp. nov. are proposed, respectively.