Jannaschia cystaugens sp. nov., an Alexandrium (Dinophyceae) cyst formation-promoting bacterium from Hiroshima Bay, Japan

Abstract

Jannaschia cystaugens sp. nov., an Alexandrium (Dinophyceae) cyst formation-promoting bacterium from Hiroshima Bay, Japan Heterotrophic bacteria isolated from water samples taken from Hiroshima Bay, Japan, and referred to as Alexandrium (Dinophyceae) cyst formation-promoting bacteria, were assigned to the Roseobacter-Sulfitobacter-Silicibacter group within the a-Proteobacteria on the basis of nearly complete 16S rRNA gene sequences. Phylogenetic analyses showed that two strains, CFPB-A9 T and CFPB-A5, are closely related to each other and that their closest relative was Jannaschia helgolandensis (95?9 % sequence similarity). These strains were Gram-negative, motile, obligately aerobic rods that required sodium ions and 2-7 % sea salts for growth and did not produce bacteriochlorophyll a. Their optimal growth temperature was 25-30 6C. The strains had Q-10 as the dominant respiratory quinone. Primary cellular fatty acid in both strains was 18 : 1v7c. The DNA G+C contents of strains CFPB-A9 T and CFPB-A5 were 59?1 and 59?2 mol%, respectively. Based on physiological, biological, chemotaxonomic and phylogenetic data, the strains are considered to represent a novel species, Jannaschia cystaugens sp. nov., with type strain CFPB-A9 T (=LMG 22015 T =NBRC 100362 T ).

Jannaschia rubra sp. nov., a red-pigmented bacterium isolated from sea water

“…Strain 4SM3 T has a G+C content of 64?6 mol%. This value is close to those determined for J. helgolandensis and J. cystaugens: 63?0 and 59?1 mol%, respectively (WagnerDöbler et al, 2003;Adachi et al, 2004).…”

“…The second most abundant fatty acid in strain 4SM3 T was 18 : 0 (8?13 %), followed by cyclo 19 : 0v8c (5?73 %), a cellular fatty acid also present in the type species of the genus Jannaschia. The latter fatty acid was not found by Adachi et al (2004) in J. cystaugens. Other fatty acids found in strain 4SM3 T are 10 : 0 3-OH (2?32 %), 16 : 0 (0?68 %), 20 : 1v7c (0?59 %) and three that are unknown: ECL 11.799 (2?19 %), ECL 15.273 (1?7 %) and ECL 17.606 (0?7 %).…”

“…The genus was defined based on its phenotypic characteristics, including unique chemotaxonomic features, and its isolated position on the phylogenetic branch of Roseobacter and related genera in the a-Proteobacteria. A second species, Jannaschia cystaugens, has been proposed by Adachi et al (2004) that includes marine isolates from the Seto inland sea in Japan. A third species of the genus is proposed here to accommodate a strain obtained from Mediterranean sea water sampled on the Spanish east coast, near Valencia.…”

Motility is involved in Silicibacter sp. TM1040 interaction with dinoflagellates

“…Members of the Roseobacter clade interact with dinoflagellates both in the environment and the laboratory (Alavi et al ., 2001; Zubkov et al ., 2001a; Adachi et al ., 2004; Miller et al ., 2004). However, little is known about the molecular mechanisms used by the bacteria to establish the interaction with the zoospore.…”

Thalassobius mediterraneus gen. nov., sp. nov., and reclassification of Ruegeria gelatinovorans as Thalassobius gelatinovorus comb. nov.

“…Novel taxa are continuously arising within this group. Thus, since that review of names, 16 proposals of novel species and nine new genera of a-3 Proteobacteria have been published in the International Journal of Systematic and Evolutionary Microbiology (Abraham et al, 2004;Adachi et al, 2004;Cho & Giovannoni, 2004;Lau et al, 2004;Lee et al, 2004;Martínez-Cánovas et al, 2004;Shieh et al, 2004;Van Trappen et al, 2004;Wagner-Döbler et al, 2004;Labrenz et al, 2005;Macián et al, 2005a, b;Pujalte et al, 2005) and a few others are currently in press. Such a concentration of papers and independent studies on the same bacterial group implies that exhaustive care has to be taken with the criteria for proposing novel taxa and their arrangement into higher rank units.…”