Danxiaibacter flavus gen. nov., sp. nov., a novel bacterium of the family Chitinophagaceae isolated from forest soil on Danxia Mountain

A Gram-stain-negative, aerobic, short rod-shaped, yellow bacterium, designated SYSU DXS3180T, was isolated from forest soil of Danxia Mountain in PR China. Growth occurred at 15-37 °C (optimum, 28-30 °C), pH 6.0-10.0 (optimum, pH 7.0-8.0) and with 0-2.0 % NaCl (optimum, 0-0.5 %, w/v). Strain SYSU DXS3180T was positive for hydrolysis of Tween 20, Tween 60, Tween 80 and starch, but negative for urease, H2S production, nitrate reduction, Tween 40 and gelatin. Phylogenetic analysis based on 16S rRNA gene and genome sequences showed that SYSU DXS3180T belonged to the family Chitinophagaceae. The closely related members were Foetidibacter luteolus YG09T (94.2 %), Limnovirga soli KCS-6T (93.9 %) and Filimonas endophytica SR 2-06T (93.7 %). The genome of strain SYSU DXS3180T was 7287640 bp with 5782 protein-coding genes, and the genomic DNA G+C content was 41.4 mol%. The main respiratory quinone was MK-7 and the major fatty acids (>10 %) were iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1 G. The major polar lipids consisted of phosphatidylethanolamine, two unidentified aminolipids and two unidentified polar lipids. Based on the phylogenetic, phenotypic and chemotaxonomic characteristics, strain SYSU DXS3180T is proposed to represent a novel species of a novel genus named Danxiaibacter flavus gen. nov., sp. nov., within the family Chitinophagaceae. The type strain is SYSU DXS3180T (=KCTC 92895T=GDMCC 1.3825 T).

Foetidibacter luteolus gen. nov., sp. nov., isolated from the rhizosphere of Salvia miltiorrhiza

A polyphosphate-producing bacterium, YG09^T, was isolated from the rhizosphere of Salvia miltiorrhiza. Its colonies were 2.0-3.0 mm in diameter, smooth, circular, convex and yellow after growth on R2A at 28 °C for 72 h, with aerobic, Gram-stain-negative, non-motile and rod-shaped bacteria. The strain was found to grow at 10-40 °C (optimum 37 °C), pH 5.5-8.0 (optimum 6.0), with 0-0.6% (w/v) NaCl (optimum 0). Chemotaxonomic analysis showed menaquinone-7 as the only quinone present; C15: 1 iso G, C15: 1 iso, C16: 0, C16: 0 3OH, C17: 0 iso 3OH, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c) as the major fatty acids (> 5%), and phosphatidylethanolamine, three unidentified phospholipids, four unidentified polar lipids, three unidentified aminolipids, and one unidentified amino phospholipid as the polar lipids. The DNA G + C content was 44.6 mol%. The 16S rRNA gene sequences of the isolate showed highest similarities to Panacibacter ginsenosidivorans Gsoil 1550^T (93.6%), Filimonas endophytica SR2-06^T (93.4%), Parasegetibacter terrae SGM2-10^T (92.8%), and Arvibacter flaviflagrans C-1-16^T (92.7%), within the family Chitinophagaceae of the phylum Bacteroidetes. The ANI values between strain YG09^T and Panacibacter ginsenosidivoran Gsoil 1550^T, Filimonas endophytica SR2-06^T and Filimonas lacunae YT21^T were 69.4, 68.3 and 68.7%, respectively. Based on phenotypic, genotypic and phylogenetic analyses, strain YG09^T represents a novel genus in the family Chitinophagaceae, for which the name Foetidibacter luteolus gen. sp. nov. is proposed. The type strain is Foetidibacter luteolus YG09^T (= MCCC 1K04042^T = KCTC 72595^T).

Filimonas effusa sp. nov., isolated from a freshwater river

Strain TTM-71^T, isolated from a freshwater river in Taiwan, was characterized using a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set (92 protein clusters) indicated that strain TTM-71^T is affiliated with species in the genus Filimonas. The 16S rRNA gene sequence similarity indicated that strain TTM-71^T is closely related to species within the genus Filimonas (94.7-95.5 % sequence similarity) and had a high sequence similarity with Filimonas endophytica SR 2-06^T (95.5 %). Strain TTM-71^T showed 70.3 % average nucleotide identity and 24.9 % digital DNA-DNA hybridization identity with Filimonas lacunae YT21^T. Cells were Gram-stain-negative, aerobic, motile by gliding, rod-shaped and formed beige-colored colonies. Optimal growth occurred at 20 °C, pH 8, and in the presence of 0.5 % NaCl. The major fatty acids of strain TTM-71^T were iso-C_15 : 0, iso-C_15 : 1 G and summed feature 3 (comprising C_16 : 1  ω7c and/or C_16 : 1  ω6c). The predominant hydroxy fatty acid was iso-C_17 : 0 3-OH. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, four uncharacterized aminophospholipids, one uncharacterized aminolipid, one uncharacterized phospholipid and one uncharacterized lipid. The predominant polyamine was homospermidine. The only isoprenoid quinone was MK-7. Genomic DNA G+C content was 45.6 mol%. On the basis of the polyphasic evidence presented, strain TTM-71^T is considered to represent a novel species of the genus Filimonas, for which the name Filimonas effusa sp. nov. is proposed. The type strain is TTM-71^T (=BCRC 81160^T=LMG 31017^T=KCTC 62871^T).

Deminuibacter soli gen. nov., sp. nov., isolated from forest soil, and reclassification of Filimonas aurantiibacter as Arvibacter aurantiibacter comb. nov

A novel strain, designated K23C18032701^T, was isolated from a sample of forest soil collected from Dinghushan Biosphere Reserve, Guangdong Province, PR China. The strain was Gram-stain-negative, aerobic, motile and showed a shape change from a filamentous cell to coccobacilli. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the novel strain belongs to the family Chitinophagaceae, and showed the highest similarities to Arvibacter flaviflagrans JCM 31293^T (95.0 %) and Filimonas aurantiibacter LMG 29039^T (94.4 %). The major cellular fatty acids included iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1 G. The predominant polar lipid was phosphatidylethanolamine (PE). The predominant respiratory quinone was menaquinone-7. The major polyamine was sym-homospermidine. The draft genome size of strain K23C18032701^T was 5.84 Mb with a DNA G+C content of 47.2 mol%. Based on phenotypic, genotypic and phylogenetic analysis, strain K23C18032701^T represents a novel species of a new genus in the family Chitinophagaceae, for which the name Deminuibacter soli is proposed. The type strain is K23C18032701^T (=GDMCC 1.1403^T=KCTC 62913^T). We also propose the reclassification of Filimonas aurantiibacter as Arvibacter aurantiibacter comb. nov. (type strain 1458^T=NRRL B-65305^T=LMG 29039^T).