Sediminibacter furfurosus gen. nov., sp. nov. and Gilvibacter sediminis gen. nov., sp. nov., novel members 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 Two Gram-negative, chemoheterotrophic, non-motile strains, Mok-1-36 T and MAOS-86 T , were isolated from marine-sediment samples collected from the coasts of Okinawa island and the city of Odawara in Japan, respectively. Phylogenetic studies based on 16S rRNA gene sequences indicated that Mok-1-36 T and MAOS-86 T were members of the family Flavobacteriaceae, clustering with members of the genera Ulvibacter and Vitellibacter, respectively. Strains Mok-1-36 T and MAOS-86 T shared pairwise 16S rRNA gene sequence similarities of 93.5 and 89.1 % with the type strains of Ulvibacter litoralis and Vitellibacter vladivostokensis, respectively. Phylogenetic distinctiveness and phenotypic differences from their phylogenetic neighbours indicated that these strains represent two novel species and genera within the family Flavobacteriaceae, for which the names Sediminibacter furfurosus gen. nov., sp. nov. (MAOS-86 T ) and Gilvibacter sediminis gen. nov., sp. nov. (Mok-1-36 T ) are proposed. The type strain of Sediminibacter furfurosus is MAOS-86 T (=NBRC 101622 T =CIP 109285 T ) and the type strain of Gilvibacter sediminis is Mok-1-36 T (=NBRC 101626 T =CIP 109286 T ). Since the description of the family Flavobacteriaceae (Reichenbach, 1992; Bernardet et al., 2002), a number of novel genera have been included. This family is one of the major branches of the phylum Bacteroidetes, and includes many marine species. They are chemoorganotrophs and play an important role in the carbon cycles of marine ecosystems (Abell & Bowman, 2005). This paper describes the characterization of two strains, Mok-1-36 T and MAOS-86 T , isolated from marine-sediment samples collected from the coasts of Okinawa island and the city of Odawara, Japan, respectively. An analysis of their physiological, chemotaxonomic and morphological proper- ties indicated that these two strains represent two novel species and genera within the family Flavobacteriaceae. Marine-sediment samples were serially diluted with sterile artificial seawater (Naigai Chemicals) and spread on half- strength marine agar (HSMA) plates [18.7 g marine broth 2216 (Difco) dissolved in 1 l artificial seawater and solidified with 1.6 % agar]. The plates were incubated at 30 u C for 5 days. Single colonies from the plates were picked and purified on plates containing the same medium at the same temperature. For routine cultivation and for most investi- gations, the same agar or the corresponding broth (HSMB) was used at the same incubation temperature. Purified strains were stored at 280 u C in artificial seawater supplemented with 20 % (v/v) glycerol. Template DNA for 16S rRNA gene analysis was prepared by using Prepman Ultra (Applied Biosystems). PCR-mediated amplification of 16S rRNA genes was carried out with primers 27f and 1492r, as described by Hiraishi et al. (1994). Amplicons were directly sequenced using the BigDye Terminator version 3.1 cycle sequencing kit and analysed on an ABI PRISM 3100 Genetic Analyzer (Applied Bio- systems). Sequences were edited and assembled using the ATGC program (Genetyx). The almost-complete 16S rRNA gene sequences thus obtained were compared with those in the DDBJ database by means of BLASTN searches (Altschul et al., 1990). Alignment with related sequences was performed using the CLUSTAL X software package (Thompson et al., 1997). Phylogenetic trees were then constructed using the neighbour-joining (Saitou & Nei, 1987) and maximum-parsimony (Swofford, 2000) methods; tree topologies were evaluated and compared using the bootstrap resampling method of Felsenstein (1985), with 1000 replicates. 16S rRNA gene sequence analysis indicated that both strains were members of the family Flavobac- teriaceae. The results of BLASTN searches against sequences in DDBJ showed Gelidibacter algens IC147 T (GenBank acces- sion no. AF001367) and Psychroserpens sp. 18III/A01/061 (AY576714) to be the closest relatives of MAOS-86 T and Mok-1-36 T , respectively showing 16S rRNA gene sequence The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequences of strain MAOS-86 T and strain Mok-1-36 T are respectively AB255369 and AB255368. 64628 G 2007 IUMS Printed in Great Britain 265 International Journal of Systematic and Evolutionary Microbiology (2007), 57, 265–269 DOI 10.1099/ijs.0.64628-0