Identification and genomic analysis of Pseudosulfitobacter koreense sp. nov. isolated from toxin-producing dinoflagellate Alexandrium pacificum

Arch Microbiol. 2023 May 20;205(6):245. doi: 10.1007/s00203-023-03583-z.


The bacterial strain AP-MA-4T isolated from the marine dinoflagellate Alexandrium pacificum (KCTC AG60911), was subjected to a taxonomic analysis. Cells of strain AP-MA-4T were Gram-stain-negative, aerobic, rod-shaped, optimum growth at 20 °C, pH 7.0, in the presence of 5% (w/v) NaCl. Strain AP-MA-4T shared the highest 16S rRNA gene sequence similarity to Pseudosulfitobacter pseudonitzschiae DSM 26824T (98.5%), followed by Ascidiaceihabitans donghaensis RSS1-M3T (96.3%), Pseudoseohaeicola caenipelagi BS-W13T (95.7%), and Sulfitobacter pontiacus CHLG 10T (95.3%). Based on 16S rRNA phylogeny, strain AP-MA-4T is phylogenetically closely related to Pseudosulfitobacter pseudonitzschiae (type species of Pseudosulfitobacter) and could be distinguished from the type species based on their phenotypic properties. The genome length of strain AP-MA-4T was 3.48 Mbp with a 62.9% G + C content. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain AP-MA-4 T and its closely related type strains were 72.2-83.3 and 18.2-27.6%, respectively. Summed feature 8 (C18:1ω7c and/or C18:1ω6c) was identified the major fatty acids (> 10%). Phosphatidylglycerol (PG), phosphatidylethanolamine (PE), and phospholipid (PL) were demonstrated as the major polar lipids. The major respiratory quinone is ubiquinone-10 (Q-10). Based on genotypic and phenotypic features, strain AP-MA-4T (= KCTC 92289T = GDMCC 1.3585T) represents a new Pseudosulfitobacter species, in which the name Pseudosulfitobacter koreense sp. nov. is proposed.

Keywords: Alexandrium pacificum; Marine dinoflagellate; Novel species; Polyphasic taxonomy.

MeSH terms

  • Bacterial Typing Techniques
  • DNA
  • DNA, Bacterial / genetics
  • Dinoflagellida* / genetics
  • Dinoflagellida* / microbiology
  • Fatty Acids / chemistry
  • Genomics
  • Phospholipids / chemistry
  • Phylogeny
  • RNA, Ribosomal, 16S / genetics
  • Sequence Analysis, DNA
  • Ubiquinone / chemistry


  • RNA, Ribosomal, 16S
  • Phospholipids
  • Fatty Acids
  • Ubiquinone
  • DNA
  • DNA, Bacterial

Supplementary concepts

  • Sulfitobacter pseudonitzschiae