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A nitrogen-fixing bacterium, designated strain SCSIO N0430T, was isolated from a mangrove sediment sample. Analysis of the sequence of the nifH gene responsible for nitrogen fixation in this strain indicated a close relationship to an uncultured bacterium ZNZ-D11 (GenBank accession no. JF896696). 16S rRNA gene sequence analysis revealed that this isolate had less than 93 % similarity to its closest relative, Sunxiuqinia elliptica DQHS4T. A phylogenetic tree reconstructed based on 16S rRNA gene sequences revealed that strain SCSIO N0430T was a member of the phylum Bacteroidetes . Chemotaxonomic and physiological characteristics, including phospholipids and major fatty acids, readily distinguished the isolate from established members of the phylum Bacteroidetes . It is concluded that strain SCSIO N0430T represents a novel genus and species, for which the name Mangrovibacterium diazotrophicum gen. nov., sp. nov. is proposed, with the type strain of the species SCSIO N0430T ( = KCTC 32129T = DSM 27148T = JCM 19152T). Based on phylogenetic characteristics and 16S rRNA gene signature nucleotide patterns, the three genera Sunxiuqinia , Prolixibacter and Mangrovibacterium are proposed to make up a novel family, Prolixibacteraceae fam. nov., in the order Bacteroidales .

A marine bacterium, designated SCSIO 03483T, was isolated from a marine sediment sample collected from the Nansha Islands in the South China Sea. The strain produced roundish colonies with diffusible yellow-coloured pigment on nutrient agar medium or marine agar 2216. Optimal growth occurred in the presence of 0–4 % (w/v) NaCl, at pH 7.0 and a temperature range of 28–37 °C. 16S rRNA gene sequence analysis indicated that the isolate belonged to the familyFlavobacteriaceaeand showed relatively high sequence similarity withImtechella halotoleransK1T(92.7 %). Phylogenetic analysis based on nearly complete 16S rRNA gene sequences revealed that the isolate shared a lineage with members of the generaImtechella,JoostellaandZhouia. Phospholipids were phosphatidylethanolamine, two unidentified aminolipids and three unknown polar lipids. The major respiratory quinone was MK-6 and the major fatty acids were iso-C15 : 0, iso-C17 : 03-OH and summed feature 3 (C16 : 1ω6c/C16 : 1ω7c). The DNA G+C content of strain SCSIO 03483Twas 38.4 mol%. On the basis of phenotypic, chemotaxonomic and molecular data, strain SCSIO 03483Trepresents a novel species in a new genus in the familyFlavobacteriaceae, for which the nameSinomicrobium oceanigen. nov., sp. nov. is proposed. The type strain ofSinobacterium oceaniis SCSIO 03483T( = KCTC 23994T = CGMCC 1.12145T).