Haliea alexandrii sp. nov., isolated from phycosphere microbiota of the toxin-producing dinoflagellate Alexandrium catenella

Abstract

A Gram-negative, aerobic, non-motile, non-spore-forming and rod-shaped bacterium, named strain LZ-16-2 T , was isolated from the phycosphere microbiota of the paralytic shellfish poisoning toxin-producing marine dinoflagellate Alexandrium catenella LZT09. Strain LZ-16-2 T grew optimally at 28 °C at pH 6.5 and with 3 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence revealed that strain LZ-16-2 T fell within the genus Haliea and was most closely related to Haliea salexigens DSM 19537 T , with which the new isolate exhibited 98.5 % 16S rRNA gene sequence similarity. The major respiratory quinone was Q-8. The predominant cellular fatty acids were C 17 : 1 ω8 c , summed feature 3 (C 16 : 1 ω7 c and/or C 16 : 1 ω6 c ), summed feature 8 (C 18 : 1 ω7 c and/or C 18 : 1 ω6 c ), C 17 : 1 ω6 c , C 11 : 0 3-OH and C 17 : 0 . The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The average nucleotide identity and in silico DNA–DNA genome hybridization relatedness values between strain LZ-16-2 T and its closest relative, H. salexigens DSM 19537 T , were 92.8 and 55.1 %, respectively. The DNA G+C content was 61.3 mol%. Differential phenotypic properties and phylogenetic distinctiveness distinguished strain LZ-16-2 T from all other members of the genus Haliea . On the basis of the polyphasic characterization, strain LZ-16-2 T represents a novel species of the genus Haliea , for which the name Haliea alexandrii sp. nov. is proposed. The type strain is LZ-16-2 T (=KCTC 62344 T =CCTCC AB2017229 T ).