Polyphasic Taxonomy Of Three Marine Bacterial Strains From The Atlantic And The Antarctic

In this study,two bacterial strains,isolated from surface seawater samples of the Atlantic Ocean,and one bacterial strain,isolated from the antarctic intertidal sediments samples,were taxonomically characterized using the polyphasic methods.Phenotypic,chemotaxonomic and genotypic characeristics of the three strains were detailedly studied and their exact taxonomic positions were finally determined.1.Polyphasic taxonomic analysis of strain SM1354TStrain SM1354T was isolated from surface seawater of the Atlantic Ocean samples.Cells of strain SM1354T were Gram-strain negative,aerobic,oxidase-and catalase-positive,non-flagellated and gliding rods.Strain SM1354T grew at 4-40?(Optimum 30?)and with 0.5-11%NaCl(w/v,Optimun 3.0%).It did not reduce nitrate to nitrite.Strain SM1354T could hydrolyse DNA,aesculin,casein,elastin,peptidoglycan,gelatin and Tween 80 but not starch and tyrosine.The strain could produce acid from arbutin,aesculin and potassium 5-ketogluconate and utilize D-glucose,D-maltose,DL-malate as sole carbon source.The major fatty acids of strain SM1354T were iso-C15:0,iso-C15:1 G,iso-C17:03-OH and C16:1?7c.Polar lipids of strain SM1354T included phosphatidylethanolamine,three unidentified lipids and one unidentified aminolipid and aminophospholipid.The major respiratory quinone of strain SM1354T was menaquinone 7(MK-7).The genomic G+C content of strain SM1354T was 33.9 mol%.Strain SM1354T shared the highest 16S rRNA sequence similarity with type strain of Marivirga tractuosa(96.2%).The phylogenetic trees based on 16S rRNA gene sequences showed that strain SM1354T,together with Marivirga tractuosa and Marivirga sericea,formed a distinct sub-branch within the family Flammeovirgaceae in the phylum Bacteroidetes.Based on the polyphasic taxonomic data,strain SM1354 represents a novel species of the genus Marivirga,for which the name Marivirga atlantica sp.nov.is proposed.The type strain of Marivirga atlantica is strain SM1354T(=CCTCC AB 2014242T = JCM30305T).2.Polyphasic taxonomic analysis of strain SM1351TStrain SM1351T was isolated from the surface seawater samples of the AtlanticOcean.Cells of SM1351T were aerobic,oxidase-and catalase-positive rods and motile by means of a single polar flagellum.Strain SM1351T grew at 4-45 ?(Optimum 35?)and with 0.5-9.0%(w/v,Optimum 3.0%)NaCl.The type strain could not reduce nitrate to nitrite.It hydrolyzed Tweens 20,40 and 60 and tyrosine but not DNA,aesculin,casein,elastin,gelatin and Tween 80.The major fatty acids of strain SM1351T were C16;1 ?7c,C17:1 ?8c,C18:1 ?7c,C16:0 and C14:0.Polar lipids of strain SM1351T inculded phosphatidylethanolamine,phosphatidylglycerol,diphosphatidylglycerol,three unidentified amino phospholipids and three unidentified lipids.The major respiratory quinone of the type strain was quinone-8(Q-8).The genomic DNA G+C content of strain SM1351T was 62.6 mol%.The 16S rRNA gene sequences analysis revealed the strain was affiliated with the genus Haliea in the family Alteromonadaceae,with sequence similarities with Haliea salexigens and Haliea Mediterranea,the two recongnized Haliea species,being 96.2%and 94.6%,respectively.In the the phylogenetic trees based on 16S rRNA gene sequences,strain SM1351T clustered with Haliea salexigens,forming a sub-cluster within the cluster encompassed by memebers of the genera Pseudohaliea,Chromatocurvus,Congregibacter and Haliea.Based on the polyphasic taxonomic data,strain SM1351T represents a novel species of the genus Haliea,for which the name Haliea atlantica sp.nov.is proposed.The type strain of Haliea atlantica is strain SM1351T(=CCTCC AB 2014266T =JCM 30304T).3.Polyphasic taxonomic analysis of strain SM1352TStrain SM1352T was isolated from the antarctic intertidal sediments samples.Cells of strain SM1352T were Gram-stained negative and oxidase-and catalase-positive,non-flagellated rods.Strain SM1352T reduced nitrate to nitrite It grew at 4-35 ?(Optimum 25 ?)and with 0.5-6.0%NaCl(w/v,Optimum 2.0%).It hydrolyzed aesculin and DNA but not casein,elastin,gelatin,tyrosine and Tween 80.Strain SM1352T possessed C15:0,iso-C15:0,anteiso-C15:0,iso-C15:1G,iso-C16:03-OH and iso-C17:03-OH as the major fatty acids.MK-6 was its predominant respiratory quinine.Polar lipids of strain SM1352T were phosphatidylethanolamine,five unidentified lipids,two unidentified amino phospholipid and one unidentified amino lipid.The DNA G+C content of strain SM1352T was 35.1 mol%.The strain shared the highest 16S rRNA gene sequence similarity with type strain of Lutibacter agarilyticus(93.2%).Phylogenetic trees based on 16S rRNA gene sequences showed that it formed a distinct branch within the cluster of Flavobacteriaceae.On the basis of the polyphasic data presented,strain SM1352T should be classified as the type strain of a novel species in a novel genus within the family Flavobacteriaceae,for which the name Magnivallibacter luteus gen.nov.,sp.nov.was proposed.The type strain of Magnivallibacter luteus was strain SM1352T(=CCTCC 2014243T=KCTC 42296T).