Four novel marine bacteria, ZZD1 T , SSM20 T , SSDWG2 T and SSMSWG5 T , were collected from seawater at Jajakdo and Minmeoru Beaches, Republic of Korea. The cells of these strains were Gram-stain-negative and rod-shaped. Strains ZZD1 T , SSM20 T , SSDWG2 T and SSMSWG5 T had the highest 16S rRNA gene sequence similarity to Pseudoalteromonas carrageenovora IAM 12662 T (16S rRNA gene sequence similarity, 99.1%), Pseudoalteromonas spongiae UST010723-006 T (99.2%), Pseudoalteromonas caenipelagi JBTF-M23 T (98.4%) and Pseudoalteromonas shioyasakiensis SE3 T (99.2%), respectively. Polyphasic and phylogenetic analyses confirmed that the four strains were closely related to the genus Pseudoalteromonas . The digital DNA–DNA hybridization values ranged from 18.9 to 22.2% for ZZD1 T , 19.1 to 26.0% for SSM20 T , 19.7 to 22.8% for SSDWG2 T and 19.7 to 34.5% for SSMSWG5 T . All values were thus below the 70% threshold, indicating distinct genomic differences between the strains. In addition, the average nucleotide identity and average amino acid identity of ZZD1 T , SSM20 T , SSDWG2 T and SSMSWG5 T with other species of the genus Pseudoalteromonas included in the phylogenetic analysis were 66.6–93.1% and 70.4–88.2%, respectively. Collectively, these results confirmed that the four strains represented new species within the genus Pseudoalteromonas . Based on these findings, the strains were classified as Pseudoalteromonas mucoides sp. nov. (type strain ZZD1 T =KACC 23717 T =TBRC 19020 T ), Pseudoalteromonas aquimarina sp. nov. (type strain SSM20 T =KACC 23718 T =TBRC 19019 T ), Pseudoalteromonas maris sp. nov. (type strain SSDWG2 T =KACC 23719 T =TBRC 19021 T ) and Pseudoalteromonas thalassia sp. nov. (type strain SSMSWG5 T =KACC 23734 T =TBRC 19022 T ).
Kim et al. (Tue,) studied this question.