We describe a new species on the basis of phenotypic characteristics and the results of an analysis of small-subunit rRNA sequences. Three strains of this organism were isolated from a culture of the toxin-producing dinoflagellate Prorocentrum lima. These bacteria are gram-negative, strictly aerobic, ovoid organisms that are motile by means of one or two subpolar flagella. They grow at temperatures ranging from 10 to 37°C and in the presence of NaCl concentrations ranging from 0.1 to 2 M and have an absolute requirement for sodium ions. They are strictly aerobic with a nonfermentative type of metabolism and are not able to grow anaerobically in presence or absence of nitrate. They do not denitrify. They exhibit oxidase, catalase, gelatinase, esculinase, β-galactosidase, and (to a lesser extent) amylase activities. The three strains which we examined require thiamine and biotin for growth. They grow only when glucose, trehalose, saccharose, fructose, maltose, pyruvate, malate, citrate, esculin, 2-ketoglutarate, 5-ketogluconate, glutamate, or shikimate is present as a sole carbon source. The three strains have identical small-subunit rRNA sequences. A phylogenetic analysis of these sequences revealed that these bacteria belong to the alpha subdivision of the Proteobacteria and that they form a distinct and robust monophyletic group with Roseobacter denitrificans and Roseobacter litoralis. This result and the general phenotypic characteristics of the organisms place them in the genus Roseobacter, although they do not produce bacteriochlorophyll a, in contrast to previously described Roseobacter species. On the basis of the phenotypic and genetic similarities of these strains, we assigned them to a single species, for which the name Roseobacter algicola is proposed. The type strain is R. algicola FF3 (= ATCC 51440).
AndersonR. D.,
BaoC.-Y.,
MinnickD. T.,
VeiglM.,
SedwickW. D.1992; Optimization of double-stranded DNA sequencing for polymerase chain reaction products. USB Editorials Comments 19:39-40–57-58
BritschgiT. B.,
GiovannoniS. J.1991; Phylogenetic analysis of a natural marine bacterioplankton population by rRNA gene cloning and sequencing. Appl. Environ. Microbiol 57:1707–1713
ColwellR. R.,
WiebeW. J.1970; Core characteristics for use in classifying aerobic, heterotrophic bacteria by numerical taxonomy. Antonie Leeuwenhoek 29:344–358
FoxG. E.,
WisotzkeyJ. D.,
JurtshukP.1992; How close is close: 16S rRNA sequence identity may not be sufficient to guarantee species identity. Int. J. Syst. Bacteriol 42:166–170
JahnK.1986; Isolation and characterization of fimbriae from Escherichia coli. 381–388SussmanM.The virulence of Escherichia coli. Reviews and methods Academic Press; London:
Rausch de TraubenbergC.1993; Interaction entre un dinoflagellé et sa microflore bactérienne associée: rôle des bactéries dans la toxicité de Prorocentrum lima Ehrenberg (Dodge). Ph.D. thesis. Université de Nantes. Nantes, France
SmibertR. M.,
KriegN. R.1981; General characterization. 409–443GerhardtP.,
MurrayR.G.E.,
CostilowR. N.,
NesterE. W.,
WoodW. A.,
KriegN. R.,
PhillipsG. B.Manual of methods for general bacteriology American Society for Microbiology; Washington, D.C.:
SmithA. B.,
LafayB.,
ChristenR.1992; Comparative variation of morphological and molecular evolution through geologic time: 28S ribo-somal RNA versus morphology in echinoids. Philos. Trans. R. Soc. London B Bio. Sci 338:365–382