Description of Endozoicomonas euniceicola sp. nov. and Endozoicomonas gorgoniicola sp. nov., bacteria isolated from the octocorals Eunicea fusca and Plexaura sp., and an emended description of the genus Endozoicomonas

Two Gram-negative, facultatively anaerobic, rod-shaped bacteria, strains EF212T and PS125T, were isolated from the octocorals Eunicea fusca and Plexaura sp., respectively. EF212T was isolated from a specimen of E. fusca collected off the coast of Florida, USA, and PS125T was isolated from a specimen of Plexaura sp. collected off the coast of Bimini, Bahamas. Analysis of the nearly full-length 16S rRNA gene sequences showed that these novel strains were most closely related to Endozoicomonas montiporae CL-33T, E. elysicola MKT110T and E. numazuensis HC50T (EF212T, 95.6–97.2 % identity; PS125T, 95.1–96.4 % identity). DNA–DNA hybridization values among EF212T, PS125T, E. montiporae LMG 24815T and E. elysicola KCTC 12372T were far below the 70 % cut-off, with all values for duplicate measurements being less than 35 %. Both EF212T and PS125T required NaCl for growth and showed optimal growth at 2–3 % NaCl, 22-30 °C and pH 8.0. The predominant cellular fatty acids were summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c), C16 : 0 and C14 : 0. The DNA G+C content of EF212T was 48.6 mol% and that of PS125T was 47.5 mol%. In addition to the genotypic differences observed between the two novel strains and related type strains, phenotypic and chemotaxonomic experiments also revealed differences between strains. Thus, strains EF212T and PS125T represent novel species of the genus Endozoicomonas , for which the names Endozoicomonas euniceicola sp. nov. and Endozoicomonas gorgoniicola sp. nov., respectively, are proposed. The type strains are EF212T ( = NCCB 100458T = DSM 26535T) for Endozoicomonas euniceicola sp. nov. and PS125T ( = NCCB 100438T = CECT 8353T) for Endozoicomonas gorgoniicola sp. nov. An emended description of the genus Endozoicomonas is also provided to encompass differences observed in the results of genotypic, chemotaxonomic and phenotypic tests compared from the original and amended genus descriptions.

Identification of the Cyclase Product and its First Oxidation Product in the Biosynthesis of Fuscol and Fuscosides

Fuscol and the related fuscosides are diterpenes isolated from the Caribbean gorgonian Eunicea fusca, which exhibit potent anti-inflammatory activity with a selective action against leukotriene production in murine models. This report describes the isolation and characterization of the diterpene cyclase product leading to these natural products. The cyclase product has been assigned the trivial name eunicene A and was identified through a radioactivity-guided isolation. Additional biosynthetic experiments conducted by incubating a cell-free extract of E. fusca with 3H-labelled metabolites confirmed the involvement of this unsaturated hydrocarbon in the production of fuscol and fuscosides.