Downloaded from www.microbiologyresearch.org by IP: 54.70.40.11 On: Fri, 25 Jan 2019 19:09:14 Planktomarina temperata gen. nov., sp. nov., belonging to the globally distributed RCA cluster of the marine Roseobacter clade, isolated from the German Wadden Sea Helge-Ansgar Giebel, 1 Daniela Kalhoefer, 1 Renate Gahl-Janssen, 1 Yoe-Jin Choo, 2 Kiyoung Lee, 2 Jang-Cheon Cho, 2 Brian J. Tindall, 3 Erhard Rhiel, 1 Christine Beardsley, 1 O ¨ mer O. Aydogmus, 1 Sonja Voget, 4 Rolf Daniel, 4 Meinhard Simon 1 and Thorsten Brinkhoff 1 Correspondence Thorsten Brinkhoff t.brinkhoff@icbm.de 1 Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, D-26111 Oldenburg, Germany 2 Division of Biology and Ocean Sciences, Inha University, Incheon, Republic of Korea 3 Leibniz Institut DSMZ – Deutsche Sammlung von Mikroorganismen und Zellkulturen, D-38124 Braunschweig, Germany 4 Institute of Microbiology & Genetics, Genomic & Applied Microbiology and Go ¨ ttingen Genomics Laboratory, University of Go ¨ ttingen, D-37077 Go ¨ ttingen, Germany Four heterotrophic bacterial strains belonging to the globally distributed marine RCA (Roseobacter clade-affiliated) cluster (family Rhodobacteraceae, class Alphaproteobacteria) were obtained from coastal seawater samples. Strain RCA23 T was isolated from a 10 ”7 dilution culture inoculated with seawater from the German Wadden Sea (southern North Sea), reflecting the high abundance of RCA bacteria in this habitat. Strains IMCC1909, IMCC1923 and IMCC1933 were isolated from diluted seawater (10 ”3 ) of the Yellow Sea, South Korea. Based on 16S rRNA gene sequence comparison, Octadecabacter antarcticus 307 T is the closest described relative of the RCA strains, with 95.4–95.5% sequence similarity. Cells of RCA23 T , IMCC1909, IMCC1923 and IMCC1933 are small motile rods requiring sodium ions. Optimal growth of RCA23 T occurs at 25 6C and within a very narrow pH range (pH 7–8, optimum pH 7.5). The DNA G+C base content of RCA23 T is 53.67 mol%. The major respiratory lipoquinone is ubiquinone-10 (Q-10) and the dominant fatty acids (.1 %) are 12 : 1 3-OH, 16 : 1v7c, 16 : 0, 18 : 1v7c, 18 : 0 and 11-methyl 18 : 1v7c. The polar lipid pattern indicated the presence of phosphatidylglycerol, two unidentified aminolipids and two unidentified phospholipids. On marine agar, RCA23 T forms non-pigmented, transparent to light beige, small (,1 mm), circular, convex colonies. Strain RCA23 T harbours all genes for the production of bacteriochlorophyll a (BChl a). Genes encoding the light-harvesting reaction centre of BChl a (pufM) were identified in all RCA strains. No visible pigmentation was observed for any of the strains under laboratory conditions, but spectrophotometric analysis revealed weak production of BChl a by RCA23 T . Morphological, physiological and genotypic features of strain RCA23 T suggest that it represents a novel species of a new genus within the Rhodobacteraceae, for which we propose the name Planktomarina temperata gen. nov., sp. nov., described previously by Giebel et al. [ISME J 5 (2011), 8–19] as ‘Candidatus Planktomarina temperata’. The type strain of Planktomarina temperata is RCA23 T (5DSM 22400 T 5JCM 18269 T ). Abbreviations: AAnP, aerobic anoxygenic photosynthesis; BChl, bacteriochlorophyll; DGGE, denaturing gradient gel electrophoresis; ITS, intergenic transcribed spacer. The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequences of strains RCA23 T , IMCC1909, IMCC1923, IMCC1933 and HTCC2150 are GQ369962, GQ468662–GQ468664 and NZ_AAXZ00000000, respectively. A supplementary table and two supplementary figures are available with the online version of this paper. International Journal of Systematic and Evolutionary Microbiology (2013), 63, 4207–4217 DOI 10.1099/ijs.0.053249-0 053249 G 2013 IUMS Printed in Great Britain 4207