ABSTRACT
Two agarolytic strains of Gram-negative, heterotrophic, facultatively anaerobic, marine bacteria, designated AAM1T and AAT1T, were isolated from seawater samples collected in the shallow coastal region of An-Ping Harbour, Tainan, Taiwan. Cells grown in broth cultures were straight rods that were motile by means of a single polar flagellum. The two isolates required NaCl for growth and grew optimally at about 25-30 degrees C, in 2-4% NaCl and at pH 8. They grew aerobically and could achieve anaerobic growth by fermenting D-glucose or other sugars. The major isoprenoid quinone was Q-8 (79.8-92.0%) and the major cellular fatty acids were summed feature 3 (C16:1omega7c and/or iso-C15:0 2-OH; 26.4-35.6%), C18:1omega7c (27.1-31.4%) and C16:0 (14.8-16.3%) in the two strains. Strains AAM1T and AAT1T had DNA G+C contents of 52.9 and 52.4 mol%, respectively. The two strains had a 16S rRNA gene sequence similarity of 98.6% and shared 84.9-92.4% sequence similarity with the type strains of Agarivorans albus (91.2-92.4%), eight Alteromonas species (84.9-87.1%), two Aestuariibacter species (86.0-87.0%), Bowmanella denitrificans (86.1-86.7%), eight Glaciecola species (85.0-87.9%) and Salinimonas chungwhensis (85.9-86.1%). Despite their high sequence similarity, strains AAM1T and AAT1T had a DNA-DNA relatedness value of only 4.5%. The data obtained from these polyphasic taxonomic studies revealed that the two agarolytic isolates could be classified as representatives of two novel species in a new genus, Aliagarivorans gen. nov., with Aliagarivorans marinus sp. nov. [type strain is AAM1T (=BCRC 17888T=JCM 15522T)] as the type species and Aliagarivorans taiwanensis sp. nov. [type strain is AAT1T (=BCRC 17889T=JCM 15537T)] as a second species.
Subject(s)
Agar/metabolism , Alteromonadaceae/classification , Alteromonadaceae/metabolism , Seawater/microbiology , Alteromonadaceae/genetics , Alteromonadaceae/isolation & purification , Anaerobiosis , Bacterial Typing Techniques , Base Composition , Cluster Analysis , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Fatty Acids/analysis , Flagella , Hydrogen-Ion Concentration , Locomotion , Molecular Sequence Data , Nucleic Acid Hybridization , Phylogeny , Quinones/analysis , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Sodium Chloride/metabolism , Taiwan , TemperatureABSTRACT
A Gram-negative, heterotrophic, agarolytic, marine bacterium, designated strain SA1T, was isolated from a seawater sample collected in the shallow coastal region of Keelung, Taiwan. Cells were straight to slightly curved rods. Nearly all of the cells were non-motile and non-flagellated during the exponential phase of growth in broth cultures; a few cells (<1 %) were motile and were considered to have monotrichous flagella. The isolate required NaCl for growth and grew optimally at 30-35 degrees C and 2-3 % (w/v) NaCl. It grew aerobically and was incapable of anaerobic growth by fermentation of glucose or other carbohydrates. However, anaerobic growth could be achieved by reduction of nitrate to nitrite. Polar lipids comprised phosphatidylethanolamine (71.8 %), diphosphatidylglycerol (12.7 %), phosphatidylglycerol (12.2 %) and phosphatidylserine (3.3 %). Isoprenoid quinones consisted of Q-10 (87.5 %), MK-9 (6.6 %) and MK-7 (5.9 %). Major cellular fatty acids were C16 : 1 omega 7c and/or iso-C15 : 0 2-OH (28.6 %), C17 : 1 omega 8c (22.8 %), C16 : 0 (14.5 %), C18 : 1 omega 7c (11.0 %) and C17 : 0 (6.4 %). The DNA G+C content was 55.6 mol%. Phylogeny based on 16S rRNA gene sequence analysis showed that strain SA1T formed a distinct lineage within the class Gammaproteobacteria. Strain SA1T was related most closely to Teredinibacter turnerae, Cellvibrio spp., Saccharophagus degradans, Pseudomonas spp. and Microbulbifer spp., strains of these species sharing <93 % 16S rRNA gene sequence similarity with strain SA1T. The phylogenetic data and those from physiological, morphological and chemotaxonomic characterizations indicated that strain SA1T represents a novel species and genus, for which the name Simiduia agarivorans gen. nov., sp. nov. is proposed. The type strain is SA1T (=BCRC 17597T=JCM 13881T).
Subject(s)
Gammaproteobacteria/classification , Gammaproteobacteria/isolation & purification , Base Composition , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Fatty Acids/metabolism , Gammaproteobacteria/genetics , Gammaproteobacteria/metabolism , Genes, Bacterial , Microscopy, Electron, Transmission , Molecular Sequence Data , Phylogeny , RNA, Bacterial/genetics , RNA, Ribosomal, 16S/genetics , Seawater/microbiology , Species Specificity , TaiwanABSTRACT
A marine agarolytic bacterium, designated strain TMA1(T), was isolated from a seawater sample collected in a shallow-water region of An-Ping Harbour, Taiwan. It was non-fermentative and Gram-negative. Cells grown in broth cultures were straight or curved rods, non-motile and non-flagellated. The isolate required NaCl for growth and exhibited optimal growth at 25 degrees C and 3 % NaCl. It grew aerobically and was incapable of anaerobic growth by fermenting glucose or other carbohydrates. Predominant cellular fatty acids were C(16 : 0) (17.5 %), C(17 : 1)omega8c (12.8 %), C(17 : 0) (11.1 %), C(15 : 0) iso 2-OH/C(16 : 1)omega7c (8.6 %) and C(13 : 0) (7.3 %). The DNA G + C content was 41.0 mol%. Phylogenetic, phenotypic and chemotaxonomic data accumulated in this study revealed that the isolate could be classified in a novel species of the genus Thalassomonas in the family Colwelliaceae. The name Thalassomonas agarivorans sp. nov. is proposed for the novel species, with TMA1(T) (=BCRC 17492(T) = JCM 13379(T)) as the type strain.
