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 toxinproducing dinoflagellate Prorocentrum Zima. 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, P-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 denitrifcans and Roseobacter Zitoralis. 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).The genus Roseobacter was created to comprise two bacterial species, Roseobacter denitriJicans and Roseobacter litoralis, which have been isolated from the surfaces of green seaweeds but not from seawater; these aerobic, pink-pigmented bacteria contain bacteriochlorophyll a (16,17). The genus Roseobacter differs phenotypically from the closely related genus Elythrobacter in carotenoid composition, bacteriochlorophyll-protein complex composition, and cell shape (16).Three bacterial strains that were isolated recently from a culture of the toxin-producing dinoflagellate Prorocentrum lima have been shown to produce okadaic acid (14). In this paper we show that on the basis of the results of a phenotypic examination and phylogenetic analyses of small-subunit rRNA these bacteria should be included in the genus Roseobacter, although none of the strains produces bacteriochlorophyll a. All of the data suggest that these three strains belong to the same new species, for which we propose the name Roseobacter algicola; strain FF3 (= ATCC 51440) is the type strain of this species. MATERIALS AND METHODSBacterial strains and growth conditions. Roseobacter algicola ML4, FF2, and FF3T (T = type strain) (14) were isolated f...

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A procedure to culture the aquatic moss, Fontinalis antipyretica, is described. The moss was collected in a stream, carried to the laboratory, and immediately treated: apices were isolated and rinsed under a stereomicroscope and submitted to ultrasonic cleaning combined with an iodine treatment and then to an antibiotic/anti-eukaryotic treatment for 4 days. This procedure permitted us for the first time to eliminate the microalgae associated with an aquatic moss in culture, solving the problem of proliferation of these microalgae in the culture medium. Furthermore, the minimal concentration of eight essential metals required by this moss was determined in order to have metal concentrations in the cultured moss as low as possible. A perennial culture of a clonal strain of an aquatic moss for use as a metal bioaccumulator was obtained and the first step to provide a standardized bioindication tool for metal detection in continental waters was passed over.

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