sp. nov., isolated from the toxigenic marine dinoflagellate LZT09.

A Gram-stain-negative, strictly aerobic, non-motile and non-pigmented spirillum, designated strain LZ-5, was isolated from cultures of the paralytic shellfish poisoning (PSP) toxin-producing marine dinoflagellate LZT09 collected from the Zhoushan sea area in the East China Sea during an algal bloom. The isolate grew at 4-40 °C (optimum, 25-33 °C) and pH 5.0-9.0 (optimum, 7.5) in the presence of 0.5-10 % (w/v) NaCl (optimum, 4.0 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain LZ-5 clearly belonged to the genus of the family . Strain LZ-5 shared highest 16S rRNA gene sequence similarity with EL-105 (98.9 %), HK-33 (97.2 %) CPA1 (96.8 %), YIM-Y25 (96.8 %) and IMCC 4453 (95.1 %). The average nucleotide identity and DNA-DNA hybridization between strain LZ-5 and the two most closely related strains, EL-105 and HK-33, were 82.2 and 19.3 %, and 72.2 and 13.2 %, respectively. The predominant respiratory quinone of strain LZ-5 was Q-8, and the major fatty acids were summed feature 8 (Cω7 and/or Cω6), summed feature 3 (Cω7 and/or Cω6) and C. The polar lipids of strain LZ-5 were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylcholine (PC), glycolipid (GL), two unidentified glycophospholipids (GPLs), three unidentified aminophospholipids (APLs) and two unidentified lipids. The genomic DNA G+C content was 57.2 mol%. On the basis of this polyphasic characterization, strain LZ-5 represents a novel species of the genus , for which the name sp. nov. is proposed. The type strain is LZ-5 (=KCTC 62460=CCTCC AB2017232).