Galbibacter mesophilus gen. nov., sp. nov., a novel member of the family Flavobacteriaceae Shams Tabrez Khan, Yasuyoshi Nakagawa and Shigeaki Harayama Correspondence Shams Tabrez Khan shams-tabrez-khan@nite.go.jp Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), 2-5-8 Kazusa-kamatari, Kisarazu, Chiba 292-0818, Japan A Gram-negative, yellow-pigmented, rod-shaped bacterial strain (Mok-17 T ) was isolated from marine sediment sampled in Okinawa Island, Japan. Based on analysis of the almost complete sequence of its 16S rRNA gene, strain Mok-17 T was found to belong to the family Flavobacteriaceae. Strain Mok-17 T showed highest 16S rRNA gene sequence similarity (91 %) to Leeuwenhoekiella marinoflava and Robiginitalea biformata. In a phylogenetic tree based on the 16S rRNA gene, strain Mok-17 T formed a deep branch distinct from all other organisms in the family Flavobacteriaceae. The major quinone was MK-6 and the major fatty acids were iso-15 : 0, iso-15 : 1, iso-17 : 0 3-OH and summed feature 3 (16 : 1v7c and/or iso-15 : 0 2-OH). The DNA G+C content was 37 mol%. The phylogenetic distance to the type strains of all recognized species in the family Flavobacteriaceae and the phenotypic properties of strain Mok-17 T supported its classification as representing a novel species in a new genus, for which the name Galbibacter mesophilus gen. nov., sp. nov. is proposed. The type strain is Mok-17 T (=NBRC 101624 T =CIP 109219 T ). Bacteria belonging to the phylum Bacteroidetes are present in high numbers in marine environments (Glo ¨ckner et al., 1999; Brown & Bowman, 2001) where they perform differ- ent functions of ecological importance. Their possible roles in the carbon cycle (Abell & Bowman, 2005), degradation of dissolved and particulate organic matter (Cottrell & Kirchman, 2000; Davey et al., 2001), fish pathology (Bernardet, 1998) and algicidal activity (Maeda et al., 1998) have been discussed. Comprising more than 50 genera at the time of writing, the family Flavobacteriaceae is one of the major branches of the phylum Bacteroidetes. Recently, new members of the family have been isolated from various marine environments (Nedashkovskaya et al., 2003, 2004, 2005). Our group has also characterized several novel species in the family, mostly from sandy sediments collected from the Pacific coasts of Japan (Khan et al., 2006a, b, c, 2007). Here we describe the isolation of a new strain, designated Mok-17 T , from a marine sediment sample collected in Okinawa Island, Japan. The sample was diluted in artificial seawater (ASW; Naigai Chemicals) and aliquots (0.1 ml) of serial dilutions were plated on marine agar 2216 (MA; Difco). Strain Mok-17 T was one of the yellow colonies that grew on the plates. Unless mentioned otherwise, plates or slants of half-strength MA (HSMA) diluted with ASW were used for routine cultivation at 30 uC. For long-term pre- servation at 280 u C, bacterial cells were suspended in ASW with 20 % (v/v) glycerol. Template DNA for 16S rRNA gene amplification was pre- pared by using Prepman Ultra (Applied Biosystems). The pair of universal primers 27f and 1492r was used to amplify the portion of the 16S rRNA gene corresponding to posi- tions 8–1492 in the Escherichia coli 16S rRNA gene sequence (Brosius et al., 1978). The amplified fragment was sequenced directly by using a BigDye Terminator v3.1 cycle sequencing kit and an ABI PRISM 3100 Genetic Analyzer (Applied Biosystems). The ATGC program (Genetyx) was used for sequence editing and assembly. The assembled sequence was then compared with the 16S rRNA gene sequences in the DNA Database of Japan (DDBJ) using BLAST searches (Altschul et al., 1990) and was aligned with related sequences by using CLUSTAL X (Thompson et al., 1997). Phylogenetic trees were inferred by using the neighbour-joining (NJ; Saitou & Nei, 1987), maximum-parsimony (MP; Swofford, 2000) and maximum-likelihood (ML; Adachi & Hasegawa, 1996) algorithms. The topology of the trees was evaluated by bootstrap resampling analysis (Felsenstein, 1985) of 1000 replicates for NJ and 100 replicates for MP and ML. The BLAST search result clearly indicated that strain Mok-17 T represented a member of the family Flavobacteriaceae. It shared highest 16S rRNA gene sequence similarity (92 %) with an unclassified bacterium, ‘Flavobacterium’ sp. (DDBJ accession no. AJ244702). Strain Mok-17 T showed highest Abbreviations: ML, maximum-likelihood; MP, maximum-parsimony; NJ, neighbour-joining. The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain Mok-17 T is AB255367. 64729 G 2007 IUMS Printed in Great Britain 969 International Journal of Systematic and Evolutionary Microbiology (2007), 57, 969–973 DOI 10.1099/ijs.0.64729-0