Methylobacter arcticus sp. nov. isolated from a coal mine biofilm in the high Arctic Svalbard

An aerobic methanotroph was isolated from a secondary sedimentation tank of a wastewater treatment plant and designated strain OY6T. Cells of OY6T were Gram-stain-negative, pink-pigmented, motile rods and contained an intracytoplasmic membrane structure typical of type I methanotrophs. OY6T could grow at a pH range of 4.5-7.5 (optimum pH 6.5) and at temperatures ranging from 20 °C to 37 °C (optimum 30 °C). The major cellular fatty acids were C14 : 0, C16 : 1ω7c/C16 : 1ω6c and C16 : 1ω5c; the predominant respiratory quinone was MQ-8. The genome size was 5.41 Mbp with a DNA G+C content of 51.7 mol%. OY6T represents a member of the family Methylococcaceae of the class Gammaproteobacteria and displayed 95.74-99.64 % 16S rRNA gene sequence similarity to the type strains of species of the genus Methylomonas. Whole-genome comparisons based on average nucleotide identity (ANI) and digital DNA-DNA hybridisation (dDDH) confirmed that OY6T should be classified as representing a novel species. The most closely related type strain was Methylomonas fluvii EbBT, with 16S rRNA gene sequence similarity, ANI by blast (ANIb), ANI by MUMmer (ANIm) and dDDH values of 99.64, 90.46, 91.92 and 44.5 %, respectively. OY6T possessed genes encoding both the particulate methane monooxygenase enzyme and the soluble methane monooxygenase enzyme. It grew only on methane or methanol as carbon sources. On the basis of phenotypic, genetic and phylogenetic data, strain OY6T represents a novel species within the genus Methylomonas for which the name Methylomonas defluvii sp. nov. is proposed, with strain OY6T (=GDMCC 1.4114T=KCTC 8159T=LMG 33371T) as the type strain.

Three Gram-negative strains, SJOD-M-6T, SJOD-M-5, and SJOD-M-33, were isolated from Ostrea denselamellosa. These strains are oxidase- and catalase-positive coccoids that thrive aerobically. The three strains shared 100.0% 16S rRNA gene sequence similarity and showed average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values of 99.7–99.8% and 93.8–96.8%, suggesting that they belonged to the same species. Phylogenetic analysis based on the 16S rRNA gene revealed that all three isolates belong to the genus Poseidonibacter. Their closest neighbors were Poseidonibacter parvus LPB0137T (98.8%), Poseidonibacter antarcticus SM1702T (98.7%), and Poseidonibacter lekithochrous LFT 1.7T (95.5%). However, the ANI and dDDH values between SJOD-M-6T (the representative strain of the novel species) and its closest phylogenetic relatives fell well below the established cut-off values of <95% (ANI) and <70% (dDDH) for species delineation. Furthermore, several phenotypic traits distinguish the novel strains from their closest relatives. Based on the combined genotypic and phenotypic data, strains SJOD-M-6T, SJOD-M-5, and SJOD-M-33 are classified as novel species within the genus Poseidonibacter. We propose the name Poseidonibacter ostreae sp. nov. for this novel species, with the type strain being SJOD-M-6T (=KCTC 72758T = NBRC 114334T = FBCC-B685).

Strain ISS653T, isolated from Atlantic seawater, is a yellow pigmented, non-motile, Gram-reaction-negative rod-shaped bacterium, strictly aerobic and chemoorganotrophic, slightly halophilic (1-15 % NaCl) and mesophilic (4-37 °C), oxidase- and catalase-positive and proteolytic. Its major cellular fatty acids are iso-C15 : 0, iso-C15 : 0 2-OH, and iso-C17 : 0 3-OH; the major identified phospholipid is phosphatidylethanolamine and the major respiratory quinone is MK6. Genome size is 4.28 Mbp and DNA G+C content is 34.9 mol%. 16S rRNA gene sequence similarity places the strain among members of the family Flavobacteriaceae, with the type strains of Mesonia phycicola (93.2 %), Salegentibacter mishustinae (93.1 %) and Mesonia mobilis (92.9 %) as closest relatives. Average amino acid identity (AAI) and average nucleotide identity (ANI) indices show highest values with M. mobilis (81 % AAI; 78.9 % ANI), M. phycicola (76 % AAI; 76.3 % ANI), Mesonia maritima (72 % AAI, 74.9 % ANI), Mesonia hippocampi (64 % AAI, 70.8 % ANI) and Mesonia algae (68 % AAI; 72.2 % ANI). Phylogenomic analysis using the Up-to-date-Bacterial Core Gene set (UBCG) merges strain ISS653T in a clade with species of the genus Mesonia. We conclude that strain ISS653T represents a novel species of the genus Mesonia for which we propose the name Mesonia oceanica sp. nov., and strain ISS653T (=CECT 9532T=LMG 31236T) as the type strain. A second strain of the species, ISS1889 (=CECT 30008) was isolated from Pacific Ocean seawater. Data obtained throughout the Tara oceans expedition indicate that the species is more abundant in the mesopelagic dark ocean than in the photic layer and it is more frequent in the South Pacific, Indian and North Atlantic oceans.

Previous studies showed that members of the Burkholderiales were important in the succession of aerobic, molybdenum-dependent CO oxidizing-bacteria on volcanic soils. During these studies, four isolates were obtained from Kilauea Volcano (Hawai‘i, USA); one strain was isolated from Pico de Orizaba (Mexico) during a separate study. Based on 16S rRNA gene sequence similarities, the Pico de Orizaba isolate and the isolates from Kilauea Volcano were provisionally assigned to the genera Burkholderia and Paraburkholderia, respectively. Each of the isolates possessed a form I coxL gene that encoded the catalytic subunit of carbon monoxide dehydrogenase (CODH); none of the most closely related type strains possessed coxL or oxidized CO. Genome sequences for Paraburkholderia type strains facilitated an analysis of 16S rRNA gene sequence similarities and average nucleotide identities (ANI). ANI did not exceed 95% (the recommended cutoff for species differentiation) for any of the pairwise comparisons among 27 reference strains related to the new isolates. However, since the highest 16S rRNA gene sequence similarity among this set of reference strains was 98.93%, DNA-DNA hybridizations (DDH) were performed for two isolates whose 16S rRNA gene sequence similarities with their nearest phylogenetic neighbors were 98.96 and 99.11%. In both cases DDH values were <16%. Based on multiple variables, four of the isolates represent novel species within the Paraburkholderia: Paraburkholderia hiiakae sp. nov. (type strain I2T = DSM 28029T = LMG 27952T); Paraburkholderia paradisi sp. nov. (type strain WAT = DSM 28027T = LMG 27949T); Paraburkholderia peleae sp. nov. (type strain PP52-1T = DSM 28028T = LMG 27950T); and Paraburkholderia metrosideri sp. nov. (type strain DNBP6-1T = DSM 28030T = LMG 28140T). The remaining isolate represents the first CO-oxidizing member of the Burkholderia cepacia complex: Burkholderia alpina sp. nov. (type strain PO-04-17-38T = DSM 28031T = LMG 28138T).

Lactobacillus kosoi Chiou et al. 2018 and Lactobacillus micheneri McFrederick et al. 2018 are closely related, and they share 100 % 16S rRNA gene sequence similarity, 99.6 % pheS gene sequence similarity, 100 % rpoA gene sequence similarity, 97.3 % average nucleotide identity (ANI) value and 76.6 % in silico DNA-DNA hybridization (isDDH) value, indicating that they represent the same species. Fatty acid methyl esters (FAME) analysis and phenotypic characterization also indicated that L. kosoi and L. micheneri are very similar. We propose L. kosoi Chiou et al. 2018 as a later heterotypic synonym of L. micheneri McFrederick et al. 2018. The taxonomic position of Lactobacillus plantarum subsp. argentoratensis in the L. plantarum group was re-examined using a polyphasic approach, including sequence analyses of 16S rRNA, pheS, rpoA and recA genes, average nucleotide identity analysis, in silico DNA-DNA hybridization, fatty acid methyl ester analysis and phenotypic characterization. Results of 16S rRNA gene sequence analysis indicated that L. plantarum subsp. argentoratensis was closely related to L. plantarum subsp. plantarum, L. pentosus and L. paraplantarum in the L. plantarum group, sharing 99.6-99.7 % 16S rRNA gene sequence similarities. Results of pheS, rpoA and recA gene sequence analyses indicated that L. plantarum subsp. argentoratensis was most closely related to L. plantarum subsp. plantarum, having 91.8 % pheS gene sequence similarity, 98.9 % rpoA gene sequence similarity and 93.1 % recA gene sequence similarity. L. plantarum subsp. argentoratensis DSM 16365T shared 95.6 % ANI value and 62.9 % isDDH value with L. plantarum subsp. plantarum ATCC 14917T. The low isDDH value confirmed that L. plantarum subsp. argentoratensis and L. plantarum subsp. plantarum represent two different species, rather than two different subspecies in the L. plantarum group. On the basis of the data from polyphasic characterization obtained in the present study and in previous studies, L. plantarum subsp. argentoratensis is elevated to the species level and represents a novel species of the genus Lactobacillus, for which the name Lactobacillus argentoratensis sp. nov. is proposed and the type strain is DKO 22T (=CIP 108320T=DSM 16365T=JCM 16169T). Two novel Gram-stain-positive bacterial strains, designated 1206-1T and F027-1-2, were isolated from traditional pickle in Heilongjiang Province, PR China, and from the intestinal tract of a honey bee (Apis mellifera) in Hubei Province, PR China, respectively. The two bacteria were characterized by a polyphasic approach, including 16S rRNA gene sequence analysis, pheS gene sequence analysis, rpoA gene sequence analysis, fatty acid methyl ester analysis, average nucleotide identity analysis, in silico DNA-DNA hybridization analysis and an analysis of phenotypic features. The results of 16S rRNA gene sequence analysis indicated that strains 1206-1T and F027-1-2 were distantly related to Lactobacillus sharpeae, Lactobacillus hulanensis, Lactobacillus songhuajiangensis, Lactobacillus pantheris, Lactobacillus thailandensis, Lactobacillus camelliae, Lactobacillus jixianensis, Lactobacillus nasuensis, Lactobacillus baoqingensis, Lactobacillus manihotivorans and Lactobacillus porcinae. Strain 1206-1T exhibited 94.2-96.4 % 16S rRNA gene sequence similarities, 69.5-83.3 % pheS gene sequence similarities and 73.1-90.3 % rpoA gene sequence similarities to type strains of phylogenetically related species. ANI and isDDH values between strain 1206-1T and the type strains of phylogenetically related species were 52.7-73.7 % and 21.1-30.1 %, respectively. On the basis of the data obtained in the present study, a novel species, Lactobacillus zhaodongensis sp. nov. is proposed and the type strain is 1206-1T (=CCM 8981T=CCTCC AB 2019200T=LMG 31620T).

Fourteen Gram-stain-positive bacterial strains were isolated from Chinese traditional pickle and yogurt. The strains were characterized using a polyphasic taxonomic approach, including 16S rRNA gene sequence analysis, pheS gene sequence analysis, rpoA gene sequence analysis, fatty acid methyl ester analysis, determination of DNA G+C content, determination of average nucleotide identity (ANI), in silico DNA-DNA hybridization (isDDH) and an analysis of phenotypic features. The data demonstrated that the 14 strains represented ten novel species belonging to the genus Lactobacillus, strains 73-4T, 247-3T, 143-4(a)T, 33-1T, 143-6T, 247-4T, 17-4T, 143-1T, 735-2T and M1530-1T were designated as the type strains. Strains 73-4T and 247-3T were phylogenetically related to the type strains of Lactobacillus camelliae and Lactobacillus jixianensis, having 97.0-98.9 % 16S rRNA gene sequence similarities, 83.9-87.2 % pheS gene sequence similarities and 86.8-93.3 % rpoA gene sequence similarities. Strains 143-4(a)T and 33-1T were phylogenetically related to the type strains of Lactobacillus rhamnosus, Lactobacillus paracasei and Lactobacillus casei, having 93.6-96.5 % 16S rRNA gene sequence similarities, 73.9-77.2 % pheS gene sequence similarities and 76.1-77.6 % rpoA gene sequence similarities. Strains 143-6T, 247-4T, 17-4T and 143-1T were phylogenetically related to the type strains of Lactobacillus concavus, Lactobacillus dextrinicus and Lactobacillus bayanensis, exhibiting 95.5-99.9 % 16S rRNA gene sequence similarities, 76.5-83.1 % pheS gene sequence similarities and 83.6-98.3 % rpoA gene sequence similarities. Strain 735-2T was phylogenetically related to the type strains of Lactobacillus zhaoyuanensis, Lactobacillus jiayinensis and Lactobacillus coryniformis, having 98.2-99.1 % 16S rRNA gene sequence similarities, 82.8-84.1 % pheS gene sequence similarities and 93.0-93.9 % rpoA gene sequence similarities. Strain M1530-1T was phylogenetically related to the type strains of Lactobacillus suantsaiihabitans and Lactobacillus brevis, having 99.5 and 99.0 % 16S rRNA gene sequence similarities, 90.3 and 81.7 % pheS gene sequence similarities and 97.7 and 91.1 % rpoA gene sequence similarities. The ANI and isDDH values between strains 73-4T, 247-3T, 143-4(a)T, 33-1T, 143-6T, 247-4T, 17-4T, 143-1T, 735-2T, M1530-1T and type strains of phylogenetically related species were less than 86.8 % and 33.9 % respectively, confirming that they represent ten novel species within the genus Lactobacillus. Based upon the data of polyphasic characterization obtained in the present study, ten novel species, Lactobacillus hegangensis sp. nov., Lactobacillus suibinensis sp. nov., Lactobacillus daqingensis sp. nov., Lactobacillus yichunensis sp. nov., Lactobacillus mulanensis sp. nov., Lactobacillus achengensis sp. nov., Lactobacillus wuchangensis sp. nov., Lactobacillus gannanensis sp. nov., Lactobacillus binensis sp. nov. and Lactobacillus angrenensis sp. nov., are proposed and the type strains are 73-4T (=NCIMB 15177T=CCM 8912T=CCTCC AB 2018407T), 247-3T (=NCIMB 15176T=JCM 33275T), 143-4(a)T (=NCIMB 15173T=CCM 8948T=JCM 33273T=CCTCC AB 2018390T), 33-1T (=NCIMB 15169T=CCM 8947T=JCM 33272T=CCTCC AB 2018405T), 143-6T (=NCIMB 15162T=CCM 8951T=JCM 33274T=CCTCC AB 2018411T), 247-4T (=NCIMB 15155T=CCM 8897T=LMG 31059T=CCTCC AB 2018410T), 17-4T (=NCIMB 15161T=CCM 8946T=JCM 33271T=CCTCC AB 2018406T), 143-1T (=NCIMB 15157T=CCM 8937T=CCTCC AB 2018409T), 735-2T (=NCIMB 15190T=CCM 8925T=LMG 31186T) and M1530-1T (=NCIMB 15150T=CCM 8893T=LMG 31046T=CCTCC AB 2018402T), respectively.

Two Gram-stain-negative, curved-rod-shaped, non-motile and aerobic bacteria W6T and I13T were isolated from marine sediment samples collected from Meishan Island located in the East China Sea. Catalase and oxidase activities and hydrolysis of Tween 40, 60 and 80 were positive for both strains, while nitrate reduction, indole production, methyl red reaction and H2S production were negative. Phylogenetic analyses based on 16S rRNA and genome sequences revealed that strains W6T and I13T formed distinct phylogenetic lineages within the genera Ascidiimonas and Leptobacterium, respectively. Strain W6T showed the closest relatedness to Ascidiimonas aurantiaca N5DA8-2CT with 93.9% 16S rRNA gene sequence similarity, 70.7% average nucleotide identity (ANI), 71.0% average amino acid identity (AAI) and 16.4% digital DNA-DNA hybridization (dDDH) values, while strain I13T was most closely related to Leptobacterium flavescens YM3-301T with 92.1% 16S rRNA gene sequence similarity, 70.5% ANI, 72.1% AAI and 17.2% dDDH values. The two novel strains shared 92.0% 16S rRNA gene sequence similarity to each other and were identified as two distinct species based on 70.7% ANI, 70.4% AAI and 17.1% dDDH values calculated using whole-genome sequences. The genomes of strains W6T and I13T were 4.59 Mbp with a G+C content of 34.5 mol% and 2.38 Mbp with a G+C content of 36.2 mol%, respectively. The only respiratory quinone was menaquinone-6, the major polar lipid was phosphatidylethanolamine and the major cellular fatty acids were iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH. Based on phenotypic, chemotaxonomic and genotypic data, strains W6T and I13T are considered to represent two novel species in the genera Ascidiimonas and Leptobacterium, respectively, in the family Flavobacteriaceae, for which the names Ascidiimonas meishanensis sp. nov. and Leptobacterium meishanense sp. nov. are proposed. The type strains are W6T (=KCTC 102201T=MCCC 1K08928T) and I13T (=KCTC 102202T=MCCC 1K08929T), respectively.

A novel Gram-stain-positive, motile, endospore-forming, rod-shaped bacterial strain, NEAU-cbsb5T, was isolated from forest soil from Changbai Mountain, Heilongjiang Province, China. The isolate grew at 15-40 °C (optimum 30 °C), at pH 6.0-8.0 (optimum pH 7.0) and in the presence of up to 4 % (w/v) NaCl, although NaCl was not required for growth. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain NEAU-cbsb5T formed a distinct lineage within the genus Bacillus and was most closely related to Bacillus acidiceler DSM 18954T (99.1 % similarity) and Bacillus luciferensis JCM 12212T (99.0 %). 16S rRNA gene sequence similarity to sequences of the type strains of other Bacillus species was less than 96.0 %. Average nucleotide identity (ANI) values between NEAU-cbsb5T and its most closely related species were 78.72-84.75 % by ANIm, ANIb and OrthoANIu analysis. The in silico DNA-DNA hybridization values between strain NEAU-cbsb5T and its close relatives B. acidiceler DSM 18954T and B. luciferensis JCM 12212T were both 23.80 %, again indicating they belong to different taxa. The major cellular fatty acids of NEAU-cbsb5T were iso-C15 : 0, anteiso-C15 : 0 and C16 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and an unknown aminophospholipid. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the predominant menaquinones were MK-7 and MK-6. The genomic DNA G+C content was 33.0 mol%. Based on the phylogenetic, phenotypic and chemotaxonomic data, strain NEAU-cbsb5T was classified as a representative of a novel species in the genus Bacillus, for which the name Bacillus solisilvae sp. nov. is proposed. The type strain is NEAU-cbsb5T (=CGMCC 1.14993T=DSM 100485T).

Two Gram-stain-negative, aerobic and yellow-pigmented bacterial strains, designated K20-16T and MSW2, were isolated from a marine red alga (Chondrus species) and seawater, respectively. Both strains were oxidase-positive, weakly catalase-positive and non-flagellated rods with gliding motility. Menaquinone-6 was detected as the sole isoprenoid quinone in both strains. Iso-C15:0, iso-C15:0 3-OH, iso-C15:1 G, C15:1 ω6c and summed feature 3 (comprising C16:1 ω7c and/or C16:1 ω6c) were identified in both strains as major fatty acids. Phosphatidylethanolamine was not identified in strain K20-16T, but it was identified in strain MSW2. The genomic DNA G+C contents of strains K20-16T and MSW2 were 30.5 and 30.7 %, respectively. Strains K20-16T and MSW2 shared 99.7% 16S rRNA gene sequence similarity, 97.7% average nucleotide identity (ANI), and 80.5% digital DNA-DNA hybridization (DDH) value, indicating that they are the same species. Phylogenetic analyses based on 16S rRNA gene and 92 concatenated core protein sequences revealed that strains K20-16T and MSW2 formed a phylogenic lineage within the genus Tenacibaculum and were most closely related to Tenacibaculum todarodis LPB0136T with 98.3 and 98.0% 16S rRNA gene sequence similarities, respectively. ANI and digital DDH values between strains K20-16T and MSW2 and other type strains were less than 91.4 and 43.1 %, respectively. Based on the phenotypic, chemotaxonomic and molecular features, strains K20-16T and MSW2 represent a novel species of the genus Tenacibaculum, for which the name Tenacibaculum aquimarinum sp. nov. is proposed. The type strain is K20-16T (=KACC 22 342T=JCM 35 023T).

A novel actinobacterium, designated strain CFH 90414T, was isolated from sediment sampled at a saline lake in Yuncheng, Shanxi, PR China. The taxonomic position of the strain was investigated by using a polyphasic approach. Cells of strain CFH 90414T were Gram-reaction-positive, aerobic and non-motile. Growth occured at 4-40 °C, pH 5.0-9.0 and in the presence of up to 0-3.0 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CFH 90414T was a member of the genus Agromyces. The 16S rRNA gene sequence similarity analysis indicated that strain CFH 90414T was most closely related to Agromyces italicus JCM 14320T (98.07 %) and Agromyces lapidis JCM 14321T (97.18 %). The whole genome of CFH 90414T was 3.64 Mb, and showed a G+C content of 71.5 mol%. The average nucleotide identity (ANI) values and digital DNA-DNA hybridization (dDDH) values between CFH 90414T and the other species of the genus Agromyces were found to be low (ANI <78.99 % and dDDH <22.9 %). The whole-cell sugars were rhamnose, mannose, ribose, glucose and galactose. The isolate contained l-2,4-diaminobutyric acid, d-alanine, d-glutamic acid and glycine in the cell-wall peptidoglycan. The predominant menaquinone was MK-12. The major cellular fatty acids were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol and an unidentified glycolipid. On the basis of phenotypic, genotypic and phylogenetic data, strain CFH 90414T is considered to represent a novel species of the genus Agromyces, for which the name Agromyces agglutinans sp. nov. is proposed. The type strain is CFH 90414T (=DSM 105966T=KCTC 49062T).

Two non-pigmented, motile, Gram-negative marine bacteria designated R9SW1T and A3d10T were isolated from sea water samples collected from Chazhma Bay, Gulf of Peter the Great, Sea of Japan, Pacific Ocean, Russia and St. Kilda Beach, Port Phillip Bay, the Tasman Sea, Pacific Ocean, respectively. Both organisms were found to grow between 4°C and 40°C, between pH 6 to 9, and are moderately halophilic, tolerating up to 20% (w/v) NaCl. Both strains were found to be able to degrade Tween 40 and 80, but only strain R9SW1T was found to be able to degrade starch. The major fatty acids were characteristic for the genus Marinobacter including C16:0, C16:1 ω7c, C18:1 ω9c and C18:1 ω7c. The G+C content of the DNA for strains R9SW1T and A3d10T were determined to be 57.1 mol% and 57.6 mol%, respectively. The two new strains share 97.6% of their 16S rRNA gene sequences, with 82.3% similarity in the average nucleotide identity (ANI), 19.8% similarity in the in silico genome-to-genome distance (GGD), 68.1% similarity in the average amino acid identity (AAI) of all conserved protein-coding genes, and 31 of the Karlin's genomic signature dissimilarity. A phylogenetic analysis showed that R9SW1T clusters with M. algicola DG893T sharing 99.40%, and A3d10T clusters with M. sediminum R65T sharing 99.53% of 16S rRNA gene sequence similarities. The results of the genomic and polyphasic taxonomic study, including genomic, genetic, phenotypic, chemotaxonomic and phylogenetic analyses based on the 16S rRNA, gyrB and rpoD gene sequence similarities, the analysis of the protein profiles generated using MALDI-TOF mass spectrometry, and DNA-DNA relatedness data, indicated that strains R9SW1T and A3d10T represent two novel species of the genus Marinobacter. The names Marinobacter salarius sp. nov., with the type strain R9SW1T ( = LMG 27497T = JCM 19399T = CIP 110588T = KMM 7502T) and Marinobacter similis sp. nov., with the type strain A3d10T ( = JCM 19398T = CIP 110589T = KMM 7501T), are proposed.

A moderately halophilic, Gram-stain-negative, aerobic bacterium, strain D1-1T, belonging to the genus Halomonas, was isolated from soil sampled at Pentha beach, Odisha, India. Phylogenetic trees reconstructed based on 16S rRNA genes and multilocus sequence analysis of gyrB and rpoD genes revealed that strain D1-1T belonged to the genus Halomonas and was most closely related to Halomonas alimentaria YKJ-16T (98.1 %) followed by Halomonas ventosae Al12T (97.5 %), Halomonas sediminicola CPS11T (97.5 %), Halomonas fontilapidosi 5CRT (97.4 %) and Halomonas halodenitrificans DSM 735T (97.2 %) on the basis of 16S rRNA gene sequence similarity. Sequence identities with other species within the genus were lower than 97.0 %. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values of 22.4-30 % and 79.5-85.4 % with close relatives of H. halodenitrificans DSM 735T, H. alimentaria YKJ-16T, H. ventosae Al12T and H. fontilapidosi 5CRT were lower than the threshold recommended for species delineation (70 % and 95-96 % for dDDH and ANI, respectively). Further, strain D1-1T formed yellow-coloured colonies; cells were rod-shaped, motile with optimum growth at 30 °C (range, 4-45 °C) and 2-8 % NaCl (w/v; grew up to 24 % NaCl). The major fatty acids were summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c), summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c) and C16 : 0 and the main respiratory quinone was ubiquinone Q-9 in line with description of the genus. Based on its chemotaxonomic and phylogenetic characteristics and genome uniqueness, strain D1-1T represents a novel species in the genus Halomonas, for which we propose the name Halomonas icarae sp. nov., within the family Halomonadaceae. The type strain is D1-1T (=JCM 33602T=KACC 21317T=NAIMCC-B-2254T).

A Gram-stain-negative, aerobic, motile, rod-shaped bacterium, designated CMS5P-6T, was isolated from a surface-sterilized bark of Aegiceras corniculatum collected from Guangxi Zhuang Autonomous Region, PR China, and investigated by a polyphasic approach to determine its taxonomic position. Strain CMS5P-6T was found to grow optimally with 0-1 % (w/v) NaCl, at 30 °C and pH 6.0-7.0. Substrate mycelia and aerial mycelia were not formed, and no diffusible pigments were observed on the media tested. Phylogenetic analysis showed that strain CMS5P-6T showed high 16S rRNA gene sequence similarity of 96.7 % to Hephaestia caeni DSM 25527T and Sphingomonas colocasiea CC-MHH0539T. The average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values between strain CMS5P-6T and H. caeni DSM 25527T were 78.0, 21.7 and 70.8 %, respectively. The average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values between strain CMS5P-6T and S. colocasiea JCM 31229T were 74.0, 19.9 and 61.4 %, respectively. Phylogenomic analyses based on genome sequences showed that strain CMS5P-6T and H. caeni DSM 25527T formed a distinct cluster within the family Sphingomonadaceae and far away from S. colocasiea JCM 31229T. The DNA G+C content of strain CMS5P-6T was determined to be 65.6 mol%. The cell-wall peptidoglycan was found to contain meso-diaminopimelic acid as the diagnostic diamino acid and ubiquinone Q-10 was identified as the respiratory lipoquinone. The polar lipids were found to comprise diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, sphingoglycolipid and two unidentified aminolipids, and the major fatty acids were identified as C18 : 1 ω7c, C19 : 0 cycloω8c and C16 : 0. On the basis of phylogenetic, genomic, chemotaxonomic and phenotypic data, strain CMS5P-6T can be concluded to represent a novel species of the genus Hephaestia, for which the name Hephaestia mangrovi sp. nov. is proposed. The type strain is CMS5P-6T (=JCM 33125T=CGMCC 1.13868T).

In paddy soil, bacteria from the family Geobacteraceae have been shown to strongly contribute to the biogeochemical cycle. However, no Geobacteraceae species with validly published names have been isolated from paddy soil. In this study, we isolated and characterized four novel ferric reducing bacteria in the family Geobacteraceae from the paddy soils of three different fields in Japan. The four strains, S43T, Red53T, S62T, and Red111T, were Gram-stain negative, strictly anaerobic, chemoheterotrophic, and motile with peritrichous flagella. Phylogenetic studies based on 16S rRNA gene sequences, five concatenated housekeeping genes (fusA, rpoB, recA, nifD, and gyrB) and 92 concatenated core genes revealed that the four strains belong to the family Geobacteraceae and are most closely related to Geobacter bemidjiensis BemT (97.4–98.2%, 16S rRNA gene sequence similarities) and Geobacter bremensis Dfr1T (97.1–98.0%). Genomic analysis with average nucleotide identity (ANI) and digital DNA–DNA hybridization (GGDC) calculations clearly distinguished the four isolated strains from other species of the family Geobacteraceae and indicated that strains S43T, Red53T, S62T, and Red111T represent independent species, with values below the thresholds for species delineation. Chemotaxonomic characteristics, including major fatty acid and whole cell protein profiles, showed differences among the isolates and their closest relatives, which were consistent with the results of DNA fingerprints and physiological characterization. Additionally, each of the four isolates shared a low 16S rRNA gene sequence similarity (92.4%) and average amino acid identity (AAI) with the type strain of the type species Geobacter metallireducens. Overall, strains S43T, Red53T, S62T, and Red111T represent four novel species, which we propose to classify in a novel genus of the family Geobacteraceae, and the names Geomonas oryzae gen. nov., sp. nov. (type strain S43T), Geomonas edaphica sp. nov. (type strain Red53T), Geomonas ferrireducens sp. nov. (type strain S62T), and Geomonas terrae sp. nov. (type strain Red111T) are proposed. Based on phylogenetic and genomic analyses, we also propose the reclassification of Geobacter bremensis as Geomonas bremensis comb. nov., Geobacter pelophilus as Geomonas pelophila comb. nov., and Geobacter bemidjiensis as Geomonas bemidjiensis comb. nov.

A Gram-stain-negative, catalase- and oxidase-positive and aerobic bacterium, designated strain R798T, was isolated from soil in South Korea. Cells were motile rods by means of a single polar flagellum. Growth of strain R798T was observed at 15-35 °C (optimum, 25-30 °C), pH 5.0-8.0 (optimum, 6.0) and 0-1.5 % NaCl (optimum, 0.3 %). Strain R798T contained ubiquinone-8 as the sole isoprenoid quinone, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and C16 : 0 as the major fatty acids and phosphatidylglycerol and phosphatidylethanolamine as the major polar lipids. The DNA G+C content of strain R798T calculated from the whole genome sequence was 63.3 mol%. Phylogenetic analyses based on the 16S rRNA gene and whole genome sequences revealed that strain R798T formed a distinct phyletic lineage within the genus Massilia. Strain R798T was most closely related to Massilia eurypsychrophila B528-3T with a 98.0 % 16S rRNA gene sequence similarity. Average nucleotide identity and digital DNA-DNA hybridization values between strain R798T and the type strain of M. eurypsychrophila were 79.2 and 22.7 %, respectively. Based on the phenotypic, chemotaxonomic and molecular analyses, strain R798T represents a novel species of the genus Massilia, for which the name Massilia soli sp. nov. is proposed. The type strain is R798T (=KACC 22114T=JCM 34601T).