Pelagibacterium halotolerans gen. nov., sp. nov. and Pelagibacterium luteolum sp. nov., novel members of the family Hyphomicrobiaceae.
Two Gram-negative, motile, aerobic bacterial strains, designated B2(T) and 1_C16_27(T), were respectively isolated from a seawater sample collected from the East China Sea and a semi-coke sample from north-eastern Estonia. Their genetic, phenotypic and chemotaxonomic properties were studied. The isolates were short rods with polar flagella and were positive for catalase and oxidase activities. Q-10 was the predominant respiratory ubiquinone. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol and two unidentified glycolipids. The major fatty acids were nonadecanoic (C(19 : 0) cyclo), octadecanoic (C(18 : 0) and C(18 : 0) 3-OH), octadecenoic (C(18 : 1)) and hexadecanoic (C(16 : 0)) acids. The G+C content of the genomic DNA was 58.1-59.3 mol%. 16S rRNA gene sequence analysis revealed that the two isolates represent a distinct lineage within the family Hyphomicrobiaceae. The phylogenetically closest relatives were Cucumibacter (92.7-93.7 % 16S rRNA gene sequence similarity), Devosia (92.9-94.4 %) and Zhangella (91.7-92.1 %). Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strains B2(T) and 1_C16_27(T) could be differentiated from each other and from members of the genera Cucumibacter, Devosia and Zhangella. Therefore, it is proposed that strains B2(T) and 1_C16_27(T) represent two novel species in a new genus, for which the names Pelagibacterium halotolerans gen. nov., sp. nov. (the type species; type strain B2(T)  = CGMCC 1.7692(T)  = JCM 15775(T)) and Pelagibacterium luteolum sp. nov. (type strain 1_C16_27(T)  = CGMCC 1.10267(T)  = JCM 16552(T)  = CELMS EEUT 1C1627(T)) are proposed.
Xu
Xue-Wei
XW
Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, People's Republic of China.|Laboratory of Marine Ecosystem and Biogeochemistry, State Oceanic Administration, Hangzhou 310012, People's Republic of China.
Huo
Ying-Yi
YY
College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China.
Wang
Chun-Sheng
CS
Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, People's Republic of China.|Laboratory of Marine Ecosystem and Biogeochemistry, State Oceanic Administration, Hangzhou 310012, People's Republic of China.
Oren
Aharon
A
Institute of Life Sciences, and the Moshe Shilo Minerva Center for Marine Biogeochemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
Cui
Heng-Lin
HL
School of Food & Biological Engineering, Jiangsu University, Zhenjiang 212013, People's Republic of China.
Vedler
Eve
E
Institute of Molecular and Cell Biology, Tartu University, Tartu 51010, Estonia.
Wu
Min
M
College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China.
D002681:China; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005227:Fatty Acids / Q000378:metabolism; D041921:Hyphomicrobiaceae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005227:Fatty Acids; D012336:RNA, Ribosomal, 16S