In Vitro Biofilm Formation on Zirconia Implant Surfaces Treated with Femtosecond and Nanosecond Lasers.

(1) Background: The purpose of this study was to evaluate how a zirconia implant surface treated with laser technology affects the degree of biofilm formation. (2) Methods: Experimental titanium (Ti) disks were produced that were sandblasted with large grit and acid-etched (T), and they were compared with zirconia (ZrO2) discs with a machined (M) surface topography; a hydrophilic surface topography with a femtosecond laser (HF); and a hydrophobic surface topography with a nanosecond laser (HN) (N = 12 per surface group). An in vitro three-species biofilm sample (Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi)) was applied to each disc type, and bacterial adhesion was assessed after 48 and 72 h of incubation using an anaerobic flow chamber model. Statistical significance was determined using the Kruskal-Wallis H test, with Bonferroni correction used for the post-hoc test (α = 0.05). (3) Results: Compared to the T group, the M group exhibited more than twice as many viable bacterial counts in the three-species biofilm samples (p < 0.05). In comparison to the T group, the HF group had significantly higher viable bacterial counts in certain biofilm samples at 48 h (Aa and Pi) and 72 h (Pi) (p < 0.05). The HN group had higher viable bacterial counts in Pi at 48 h (5400 CFU/mL, p < 0.05) than the T group (4500 CFU/mL), while showing significantly lower viable bacterial counts in Pg at both 48 (3010 CFU/mL) and 72 h (3190 CFU/mL) (p < 0.05). (4) Conclusions: The surface treatment method for zirconia discs greatly influences biofilm formation. Notably, hydrophobic surface treatment using a nanosecond laser was particularly effective at inhibiting Pg growth.

Genome insight and probiotic potential of three novel species of the genus Corynebacterium.

Three bacterial strains, B5-R-101T, TA-R-1T, and BL-R-1T, were isolated from the feces of a healthy Korean individual. Cells of these strains were Gram-stain-positive, facultatively anaerobic, oxidase-negative, catalase-positive, rod-shaped, and non-motile. They were able to grow within a temperature range of 10-42°C (optimum, 32-37°C), at a pH range of 2.0-10.0 (optimum, pH 5.5-8.0), and at NaCl concentration of 0.5-10.5% (w/v). All the three strains exhibited 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities ranging from 58 ± 1.62 to 79 ± 1.46% (% inhibition). These strains survived in lower pH (2.0) and in 0.3% bile salt concentration for 4 h. They did not show hemolytic activity and exhibited antimicrobial activity against pathogenic bacteria, such as Escherichia coli, Acinetobacter baumannii, Staphylococcus aureus, and Salmonella enterica. The genomic analysis presented no significant concerns regarding antibiotic resistance or virulence gene content, indicating these strains could be potential probiotic candidates. Phylogenetic analysis showed that they belonged to the genus Corynebacterium, with 98.5-99.0% 16S rRNA gene sequence similarities to other members of the genus. Their major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The abundant cellular fatty acids were C16:0, C18:1ω9c, and anteiso-C19:0. Genomic analysis of these isolates revealed the presence of genes necessary for their survival and growth in the gut environment, such as multi-subunit ATPases, stress response genes, extracellular polymeric substance biosynthesis genes, and antibacterial genes. Furthermore, the genome of each strain possessed biosynthetic gene clusters with antioxidant and antimicrobial potentials, including terpenes, saccharides, polyketides, post-translationally modified peptides (RIPPs), and non-ribosomal peptides (NRPs). In silico DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values were lower than the thresholds to distinguish novel species. Based on phenotypic, genomic, phylogenomic, and phylogenetic analysis, these potential probiotic strains represent novel species within the genus Corynebacterium, for which the names Corynebacterium intestinale sp. nov. (type strain B5-R-101T = CGMCC 1.19408T = KCTC 49761T), Corynebacterium stercoris sp. nov. (type strain TA-R-1T = CGMCC 1.60014T = KCTC 49742T), and Corynebacterium faecium sp. nov. (type strain BL-R-1T = KCTC 49735T = TBRC 17331T) are proposed.

Influence of Dental Titanium Implants with Different Surface Treatments Using Femtosecond and Nanosecond Lasers on Biofilm Formation.

This study aimed to evaluate the impact of different surface treatments (machined; sandblasted, large grit, and acid-etched (SLA); hydrophilic; and hydrophobic) on dental titanium (Ti) implant surface morphology, roughness, and biofilm formation. Four groups of Ti disks were prepared using distinct surface treatments, including femtosecond and nanosecond lasers for hydrophilic and hydrophobic treatments. Surface morphology, wettability, and roughness were assessed. Biofilm formation was evaluated by counting the colonies of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), and Prevotella intermedia (Pi) at 48 and 72 h. Statistical analysis was conducted to compare the groups using the Kruskal-Wallis H test and the Wilcoxon signed-rank test (α = 0.05). The analysis revealed that the hydrophobic group had the highest surface contact angle and roughness (p < 0.05), whereas the machined group had significantly higher bacterial counts across all biofilms (p < 0.05). At 48 h, the lowest bacterial counts were observed in the SLA group for Aa and the SLA and hydrophobic groups for Pg and Pi. At 72 h, low bacterial counts were observed in the SLA, hydrophilic, and hydrophobic groups. The results indicate that various surface treatments affect implant surface properties, with the hydrophobic surface using femtosecond laser treatment exerting a particularly inhibitory effect on initial biofilm growth (Pg and Pi).

Insight into gut dysbiosis of patients with inflammatory bowel disease and ischemic colitis.

The collection of whole microbial communities (bacteria, archaea, fungi, and viruses) together constitutes the gut microbiome. Diet, age, stress, host genetics, and diseases cause increases or decreases in the relative abundance and diversity of bacterial species (dysbiosis). We aimed to investigate the gut microbial composition at different taxonomic levels of healthy controls (HCs) with active Crohn's disease (CD), ulcerative colitis (UC), and ischemic colitis (IC) using culture- and non-culture-based approaches and identify biomarkers to discriminate CD, UC, or IC. We determined the specific changes in the gut microbial profile using culture-independent (16S rRNA gene amplicon sequencing) as well as culture-based (culturomic) approaches. Biomarkers were validated using quantitative Real-Time PCR (qPCR). In both methods, bacterial diversity and species richness decreased in disease-associated conditions compared with that in HCs. Highly reduced abundance of Faecalibacterium prausnitzii and Prevotella sp. and an increased abundance of potentially pathogenic bacteria such as Enterococcus faecium, Enterococcus faecalis, and Escherichia coli in all CD, UC, or IC conditions were observed. We noted a high abundance of Latilactobacillus sakei in CD patients; Ligilactobacillus ruminis in UC patients; and Enterococcus faecium, Escherichia coli, and Enterococcus faecalis in IC patients. Highly reduced abundance of Faecalibacterium prausnitzii in all cases, and increased abundance of Latilactobacillus sakei and Enterococcus faecium in CD, Ligilactobacillus ruminis and Enterococcus faecium in UC, and Enterococcus faecium, Escherichia coli, and Enterococcus faecalis in IC could be biomarkers for CD, UC, and IC, respectively. These biomarkers may help in IBD (CD or UC) and IC diagnosis.

Differentiation of Escherichia fergusonii and Escherichia coli Isolated from Patients with Inflammatory Bowel Disease/Ischemic Colitis and Their Antimicrobial Susceptibility Patterns.

Genotypically, 16S rRNA gene sequence analysis clearly differentiates between species. However, species delineation between Escherichia fergusonii and Escherichia coli is much more difficult and cannot be distinguished by 16S rRNA gene sequences alone. Hence, in this study, we attempted to differentiate E. fergusonii and E. coli isolated from faecal samples of disease-associated Korean individuals with inflammatory bowel disease (IBD)/ischemic colitis (IC) and test the antimicrobial susceptibility patterns of isolated strains. Phylogenetic analysis was performed using the adenylate kinase (adk) housekeeping gene from the E. coli multi locus sequence typing (MLST) scheme. Antimicrobial susceptibility and minimum inhibitory concentration (MIC) of all disease-associated strains in addition to healthy control isolates to 14 antibiotics were determined by broth microdilution-based technique. Next, 83 isolates from 11 disease-associated faecal samples were identified as E. fergusonii using 16S rRNA gene sequence analysis. Phylogenetic analysis using the adk gene from E. coli MLST scheme revealed that most of the strains (94%) were E. coli. A total of 58 resistance patterns were obtained from 83 strains of disease-associated (IBD/IC) isolates. All isolates were resistant to at least one tested antimicrobial agent, with the highest resistance against erythromycin (88.0%), ampicillin (86.7%), ciprofloxacin (73.5%), cephalothin (72.3%), gentamicin (59%), trimethoprim-sulfamethoxazole (53%), cefotaxime (49.4%), and ceftriaxone (48.2%). A total of 90.7% of isolates were extended-spectrum beta-lactamase (ESBL)-producers among the resistant strains to third-generation cephalosporins (cefotaxime or ceftriaxone). ESBL-producing E. coli isolates from patients with Crohn's disease (CD), ulcerative colitis (UC), and ischemic colitis (IC) were 92.3%, 82.4%, and 100%, respectively. In conclusion, adk-based phylogenetic analysis may be the most accurate method for distinguishing E. coli and E. fergusonii from Escherichia genus. We identified four loci in adk gene sequences which makes it easier to discriminate between E. coli and E. fergusonii. Additionally, we believe that gut colonization by multidrug-resistant ESBL-producing E. coli may play a significant role in IBD/IC pathogenesis.

Genome mining revealed polyhydroxybutyrate biosynthesis by Ramlibacter agri sp. nov., isolated from agriculture soil in Korea.

A white-colony-forming, facultative anaerobic, motile and Gram-stain-negative bacterium, designated G-1-2-2 T was isolated from soil of agriculture field near Kyonggi University, Republic of Korea. Strain G-1-2-2 T synthesized the polyhydroxybutyrate and could grow at 10-35 °C. The phylogenetic analysis based on 16S rRNA gene sequence showed that, strain G-1-2-2 T formed a lineage within the family Comamonadaceae and clustered as a member of the genus Ramlibacter. The 16S rRNA gene sequence of strain G-1-2-2 T showed high sequence similarities with Ramlibacter ginsenosidimutans BXN5-27 T (97.9%), Ramlibacter monticola G-3-2 T (97.9%) and Ramlibacter alkalitolerans CJ661T (97.5%). The sole respiratory quinone was ubiquinone-8 (Q-8). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, and an unidentified phospholipid. The principal cellular fatty acids were C16:0, cyclo-C17:0, summed feature 3 (C16:1ω7c and/or C16:1ω6c) and summed feature 8 (C18:1ω7c and/or C18:1ω6c). The genome of strain G-1-2-2 T was 7,200,642 bp long with 13 contigs, 6,647 protein-coding genes, and DNA G + C content of 68.9%. The average nucleotide identity and in silico DNA-DNA hybridization values between strain G-1-2-2 T and close members were ≤ 81.2 and 24.1%, respectively. The genome of strain G-1-2-2 T showed eight putative biosynthetic gene clusters responsible for various secondary metabolites. Genome mining revealed the presence of atoB, atoB2, phaS, phbB, phbC, and bhbD genes in the genome which are responsible for polyhydroxybutyrate biosynthesis. Based on these data, strain G-1-2-2 T represents a novel species in the genus Ramlibacter, for which the name Ramlibacter agri sp. nov. is proposed. The type strain is G-1-2-2 T (= KACC 21616 T = NBRC 114389 T).

Cellulomonas fulva sp. nov., isolated from oil-contaminated soil.

A yellow-coloured, Gram-stain-positive, motile, aerobic and rod-shaped bacteria, designated DKR-3T, was isolated from oil-contaminated experimental soil. Strain DKR-3T could grow at pH 5.0-10.5 (optimum, pH 7.0-8.5), at 10-40 °C (optimum, 25-32 °C) and tolerated 3.5 % of NaCl. Phylogenetic analyses based on its 16S rRNA gene sequence indicated that strain DKR-3T formed a lineage within the family Cellulomonadaceae and was clustered with members of the genus Cellulomonas. Strain DKR-3T had highest 16S rRNA gene sequence similarities to Cellulomonas gelida DSM 20111T (98.3 %), Cellulomonas persica JCM 18111T (98.2 %) and Cellulomonas uda DSM 20107T (97.8 %). The predominant respiratory quinone was tetrahydrogenated menaquinone with nine isoprene units [MK-9(H4)]. The principal cellular fatty acids were anteiso-C15 : 0, C16 : 0 and anteiso-C17 : 0. The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The cell-wall diamino acid was l-ornithine whereas rhamnose and glucose were the cell-wall sugars. The DNA G+C content was 74.2mol %. The genome of strain DKR-3T was 3.74 Mb and contained three putative biosynthetic gene clusters. The average nucleotide identity and digital DNA-DNA hybridization relatedness values between strain DKR-3T and its phylogenetically related members were below the species threshold values. Based on a polyphasic study, strain DKR-3T represents a novel species belonging to the genus Cellulomonas, for which the name Cellulomonas fulva sp. nov. is proposed. The type strain is DKR-3T (=KACC 22071T=NBRC 114730T).

Kaistella soli sp. nov., isolated from oil-contaminated experimental soil.

A light yellow-coloured, non-motile, aerobic, Gram-stain-negative, and rod-shaped bacterial strain DKR-2T was isolated from oil-contaminated experimental soil. The strain was catalase and oxidase positive, and grew at 0-1.5% (w/v) NaCl concentration, at temperature 10-35 °C, and at pH 6.0-9.5. The phylogenetic analysis suggested that the strain DKR-2T was affiliated to the genus Kaistella, with the closest species being Kaistella haifensis DSM 19056T (97.6% 16S rRNA gene sequence similarity). The principle fatty acids were iso-C15:0, summed feature 9 (iso-C17:1 ω9c and/or C16:0 10-methyl), and antiso-C15:0. The sole menaquinone was MK-6 and major polar lipid was phosphatidylethanolamin. The DNA G+C content was 39.5%. The dDDH (in silico DNA-DNA hybridization) and ANI (average nucleotide identity) values between strain DKR-2T and K. haifensis DSM 19056T were 22.4% and 79.3%, respectively. In addition, both dDDH and ANI values between strain DKR-2T and other phylogenetically related neighbours were < 25.0% and < 77.0%, respectively. In overall, the polyphasic taxonomic data presented in this study clearly indicated that strain DKR-2T represents a novel species in the genus Kaistella, for which the name Kaistella soli sp. nov. is proposed. The type strain is DKR-2T (=KACC 22070T=NBRC 114725T).

Description of antibiotic-producing novel bacteria Paraburkholderia antibiotica sp. nov. and Paraburkholderia polaris sp. nov.

Two white colony-forming, Gram-stain-negative, non-sporulating and motile bacteria, designated G-4-1-8T and RP-4-7T, were isolated from forest soil and Arctic soil, respectively. Both strains showed antimicrobial activity against Gram-negative pathogens (Pseudomonas aeruginosa and Escherichia coli) and could grow at a pH range of pH 4.0-11.0 (optimum, pH 7.0-9.0). Phylogenetic analyses based on their 16S rRNA gene sequences indicated that strains G-4-1-8T and RP-4-7T formed a lineage within the family Burkholderiaceae and were clustered as members of the genus Paraburkholderia. Strain G-4-1-8T showed the highest 16S rRNA sequence similarity to Paraburkholderia monticola JC2948T (98.1 %), while strain RP-4-7T showed the highest similarity to Paraburkholderia metrosideri DNBP6-1T (98.8 %). The only respiratory quinone in both strains was ubiquinone Q-8. Their principal cellular fatty acids were C16 : 0, cyclo-C17 : 0, summed feature 3 (iso-C15 :0 2-OH and/or C16 :1 ω7c) and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). Their major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and an unidentified aminophospholipid. The DNA G+C content of strains G-4-1-8T and RP-4-7T were 63.7 and 61.3 mol%, respectively, while their genome lengths were 7.44 and 9.67 Mb, respectively. The genomes of both strains showed at least 12 putative biosynthetic gene clusters. The average nucleotide identity and in silico DNA-DNA hybridization relatedness values between both strains and most closely related Paraburkholderia species were below the species threshold values. Based on a polyphasic study, these isolated strains represent novel species belonging to the genus Paraburkholderia, for which the names Paraburkholderia antibiotica sp. nov. (G-4-1-8T= KACC 21617T=NBRC 114603T) and Paraburkholderia polaris sp. nov. (RP-4-7T=KACC 21621T=NBRC 114605T) are proposed.

Cold-shock gene cspC in the genome of Massilia polaris sp. nov. revealed cold-adaptation.

A straw coloured, motile and Gram-stain-negative bacterium, designated RP-1-19T was isolated from soil of Arctic station, Svalbard, Norway. Based on the phylogenetic analysis of its 16S rRNA gene sequence, strain RP-1-19T formed a lineage within the family Oxalobacteraceae and clustered together within the genus Massilia. The closest members were M. violaceinigra B2T (98.6% sequence similarity), M. eurypsychrophilia JCM 30074T (98.3%) and M. atriviolacea SODT (98.1%). The only respiratory quinone was ubiquinone-8. The principal cellular fatty acids were summed feature 3 (iso-C15:0 2-OH/C16:1ω7c) and C16:0. The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The DNA G + C content of the type strain was 63.2%. The average nucleotide identity and in silico DNA-DNA hybridization values between strain RP-1-19T and closest members were ≤ 80 and 23.2%, respectively. The genome was 4,522,469 bp long with 30 scaffolds and 4076 protein-coding genes. The genome showed eight putative biosynthetic gene clusters responsible for various secondary metabolites. Genome analysis revealed the presence of cold-shock proteins CspA and CspC. Presence of cspA and cspC genes in the genome manifest ecophysiology of strain RP-1-19T that may help in cold-adaptation. Based on these data, strain RP-1-19T represents a novel species in the genus Massilia, for which the name Massilia polaris sp. nov. is proposed. The type strain is RP-1-19T (= KACC 21619T = NBRC 114359T).

Azohydromonas caseinilytica sp. nov., a Nitrogen-Fixing Bacterium Isolated From Forest Soil by Using Optimized Culture Method.

A bacterial strain, designated strain G-1-1-14T, was isolated from Kyonggi University forest soil during a study of previously uncultured bacterium. The cells of strain G-1-1-14T were motile by means of peritrichous flagella, Gram-stain-negative, rod-shaped, and able to grow autotrophically with hydrogen and fix nitrogen. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain G-1-1-14T belonged to the genus Azohydromonas. The closest species of strain G-1-1-14T were Azohydromonas ureilytica UCM-80 T (98.4% sequence similarity), Azohydromonas lata IAM 12599 T (97.5%), Azohydromonas riparia UCM-11 T (97.1%), and Azohydromonas australica IAM 12664 T (97.0%). The genome of strain G-1-1-14T was 6,654,139 bp long with 5,865 protein-coding genes. The genome consisted of N2-fixing genes (nifH) and various regulatory genes for CO2 fixation and H2 utilization. The principal respiratory quinone was ubiquinone-8, and the major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, and phosphatidylglycerol. The major fatty acids were summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1 ω7c), C16 : 0, summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), and cyclo-C17 : 0. The DNA G + C content was 69.9%. The average nucleotide identity (OrthoANI), in silico DNA-DNA hybridization (dDDH), and conventional DDH relatedness values were below the species demarcation values for novel species. Based on genomic, genetic, phylogenetic, phenotypic, and chemotaxonomic characterizations, strain G-1-1-14T represents a novel species within the genus Azohydromonas, for which the name Azohydromonas caseinilytica sp. nov. is proposed. The type strain is G-1-1-14T (= KACC 21615 T = NBRC 114390 T ).

Aquabacterium terrae sp. nov., isolated from soil.

A yellow-colored bacterial strain, designated S2T was isolated from soil in South Korea. Cells of strain S2T were strictly aerobic, Gram-stain-negative, motile with single polar flagellum, rod-shaped, oxidase and catalase-negative. Growth occurs at 10-37 °C (optimum, 28 °C), pH 5.0-9.0 (optimum, pH 6.5-7.0) and 0-3% NaCl (w/v). Strain S2T consisted of summed feature 3 (iso-C15:0 2-OH and/or C16:1 ω7c), C16:0 and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c) as major fatty acids. The sole respiratory quinone was Q-8. The polar lipid profile consisted of phosphatidylethanolamine and an unidentified lipid. The 16S rRNA gene sequence analysis showed that strain S2T is phylogenetically closest to Aquabacterium pictum W35T (98.4% sequence similarity). The genome of strain S2T was 8,039,486 bp with 56 scaffolds. The genome consisted of 10 putative biosynthetic gene clusters that are responsible for various secondary metabolites. Genomic DNA G + C content of strain S2T was 69.4%. The average nucleotide identity and in silico DNA-DNA hybridization values between strain S2T and phylogenetically related taxa were ≤ 77.9 and ≤ 21.4%, and respectively. The results of genotypic and phenotypic data showed that strain S2T could be distinguished from its phylogenetically related species and represents a novel species in the genus Aquabacterium, for which the name Aquabacterium terrae sp. nov. is proposed. The type strain is S2T (= KCTC 72741 T = NBRC 114609 T).

Genome insight and description of antibiotic producing Massilia antibiotica sp. nov., isolated from oil-contaminated soil.

An ivory-coloured, motile, Gram-stain-negative bacterium, designated TW-1T was isolated from oil-contaminated experimental soil in Kyonggi University. The phylogenetic analysis based on 16S rRNA gene sequence revealed, strain TW-1T formed a lineage within the family Oxalobacteraceae and clustered as members of the genus Massilia. The closest members were M. pinisoli T33T (98.8% sequence similarity), M. putida 6NM-7T (98.6%), M. arvi THG-RS2OT (98.5%), M. phosphatilytica 12-OD1T (98.3%) and M. niastensis 5516S-1T (98.2%). The sole respiratory quinone is ubiquinone-8. The major cellular fatty acids are hexadeconic acid, cis-9, methylenehexadeconic acid, summed feature 3 and summed feature 8. The major polar lipids are phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The DNA G + C content of the type strain is 66.3%. The average nucleotide identity (ANI) and in silico DNA-DNA hybridization (dDDH) relatedness values between strain TW-1T and closest members were below the threshold value for species demarcation. The genome size is 7,051,197 bp along with 46 contigs and 5,977 protein-coding genes. The genome showed 5 putative biosynthetic gene clusters (BGCs) that are responsible for different secondary metabolites. Cluster 2 showed thiopeptide BGC with no known cluster blast, indicating TW-1T might produce novel antimicrobial agent. The antimicrobial assessment also showed that strain TW-1T possessed inhibitory activity against Gram-negative pathogens (Escherichia coli and Pseudomonas aeruginosa). This is the first report of the species in the genus Massilia which produces antimicrobial compounds. Based on the polyphasic study, strain TW-1T represents novel species in the genus Massilia, for which the name Massilia antibiotica sp. nov. is proposed. The type strain is TW-1T (= KACC 21627T = NBRC 114363T).

Noviherbaspirillum pedocola sp. nov., isolated from oil-contaminated experimental soil.

An orange-coloured, rod-shaped, and aerobic bacterial strain DKR-6 T was isolated from oil-contaminated experimental soil. The strain was Gram-stain-negative, catalase and oxidase positive, and grew at temperature 10-42 °C, at pH 5.5-9.5, and at 0-3.0% (w/v) NaCl concentration. The phylogenetic analysis and 16S rRNA gene sequence analysis suggested that the strain DKR-6 T was affiliated to the genus Noviherbaspirillum, with the closest species being Noviherbaspirillum massiliense JC206T (96.3% sequence similarity). The chemotaxonomic profiles revealed the presence of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, and phosphatidylcholine as the principal polar lipids; C16:0, C17:0 cyclo, summed feature 3 (C16:1ω7c and/or C16: 1ω6c), and summed feature 8 (C18:1ω7c/or C18:1ω6c) as the main fatty acids; and Q-8 as a sole ubiquinone. The DNA G + C content was 61.6%. The polyphasic taxonomic features illustrated in this study clearly implied that strain DKR-6 T represents a novel species in the genus Noviherbaspirillum, for which the name Noviherbaspirillum pedocola sp. nov. is proposed with the type strain DKR-6 T (= KACC 22074 T = NBRC 114727 T).

Schlegelella koreensis sp. nov., isolated from evaporator core of automobile air conditioning system.

A white-coloured, aerobic, and rod-shaped bacterium, designated strain ID0723T was isolated from evaporator core of automobile air conditioning system. The strain was Gram-stain-negative, catalase positive, oxidase negative, and grew at pH 5.5-9.5, at temperature 18-37 °C, and at 0-2.0% (w/v) NaCl concentration. The phylogenetic analysis and 16S rRNA gene sequence data revealed that the strain ID0723T was affiliated to the genus Schlegelella, with the closest phylogenetic member being Schlegelella brevitalea DSM 7029 T (98.1% sequence similarity). The chemotaxonomic features of strain ID0723T were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine as the main polar lipids; Q-8 as an only ubiquinone; and summed feature 3 (C16:1ω7c and/or C16: 1ω6c), C16:0, and summed feature 8 (C18:1ω7c/or C18:1ω6c) as the major fatty acids. The average nucleotide identity (ANI) and in silico DNA-DNA hybridization values between strain ID0723T and S. brevitalea DSM 7029 T were 74.8% and 20.0%, respectively, which were below the cut-off values of 95% and 70%, respectively. The DNA G + C content was 69.9 mol%. The polyphasic taxonomic data clearly indicated that strain ID0723T represents a novel species in the genus Schlegelella for which the name Schlegelella koreensis sp. nov. is proposed, with the type strain ID0723T (= KCTC 72731 T = NBRC 114611 T).

Chitinophaga fulva sp. nov., isolated from forest soil.

An aerobic, Gram-stain-negative, oxidase- and catalase-positive, non-motile, non-spore-forming, rod-shaped and yellow-coloured bacterium designated strain G-6-1-13T was isolated from Gwanggyo mountain forest soil. Strain G-6-1-13T could grow at 15-40 °C (optimum, 20-32 °C), pH 4.5-10.5 (optimum, pH 6.0-9.0), at 2 % (w/v) NaCl concentration, and produced flexirubin-type pigments. Phylogenetic analysis based on its 16S rRNA gene sequence showed that strain G-6-1-13T formed a lineage within the genus Chitinophaga that was distinct from other species of the genus. Closest member was Chitinophaga varians 10-7 W-9003T (98.6 % sequence similarity) followed by C. eiseniae DSM 22224T (98.4 %), C. qingshengii JN246T (97.6 %) and C. terrae KP01T (97.4%). The major cellular fatty acids were iso-C15 : 0, C16 : 1 ω5c, and summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1 ω6c). MK-7 was the sole respiratory quinone. The major polar lipids were phosphatidylethanolamine and an unidentified phospholipid. The DNA G+C content of strain G-6-1-13T was 48.7 mol%. Average nucleotide identity and in silico DNA-DNA hybridization were below the species threshold. On the basis of phenotypic, genotypic, phylogenetic and chemotaxonomic characterization, G-6-1-13T represents a novel species in the genus Chitinophaga, for which the name Chitinophaga fulva sp. nov. is proposed. The type strain is G-6-1-13T (=KACC 21624T=NBRC 114361T).

Genome Sequence of Hymenobacter polaris RP-2-7T, Isolated from Arctic Soil.

Hymenobacter polaris RP-2-7T was isolated from soil from the Arctic region. This study presents the genome sequence of Hymenobacter polaris RP-2-7T, generated using the Illumina HiSeq platform. The genome size is 5,587,174 bp; it contains 4,721 genes and has 62.8 mol% DNA G+C content.

Novosphingobium olei sp. nov., with the ability to degrade diesel oil, isolated from oil-contaminated soil and proposal to reclassify Novosphingobium stygium as a later heterotypic synonym of Novosphingobium aromaticivorans.

Two yellow-pigmented, non-motile, Gram-stain-negative, and rod-shaped bacteria, designated TW-4T and TNP-2 were obtained from oil-contaminated soil. Both strains degrade diesel oil, hydrolyse aesculin, DNA, Tween 40 and Tween 60. A phylogenetic analysis based on its 16S rRNA gene sequence revealed that strain TW-4T formed a lineage within the family Erythrobacteraceae and clustered as members of the genus Novosphingobium. The closest members of strain TW-4T were Novosphingobium subterraneum DSM 12447T (97.9 %, sequence similarity), Novosphingobium lubricantis KSS165-70T (97.8 %), Novosphingobium taihuense T3-B9T (97.8 %), Novosphingobium aromaticivorans DSM 12444T (97.7 %), Novosphingobium flavum UCT-28T (97.7 %), and Novosphingobium bradum STM-24T (97.6 %). The sequence similarity for other members was ≤97.6 %. The genome of strain TW-4T was 4 683 467 bp long with 44 scaffolds and 4280 protein-coding genes. The sole respiratory quinone was Q-10. The major cellular fatty acids were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C16 : 0 and C14 : 0 2-OH. The major polar lipids were phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), phosphatidylcholine (PC), phosphatidyl-n-methylethanolamine (PME) and sphingoglycolipid (SGL). The DNA G+C content of the type strain was 65.0 %. The average nucleotide identity (ANIu) and in silico DNA-DNA hybridization (dDDH) relatedness values between strain TW-4T and closest members were below the threshold value for species delineation. Based on polyphasic taxonomic analyses, strain TW-4T represents novel species in the genus Novosphingobium, for which the name Novosphingobium olei sp. nov. is proposed. The type strain is TW-4T (=KACC 21628T=NBRC 114364T) and strain TNP-2 (=KACC 21629=NBRC 114365) represents an additional strain. Based on new data obtained in this study, it is also proposed to reclassify Novosphingobium stygium as a later heterotypic synonym of Novosphingobium aromaticivorans.

Chryseobacterium cheonjiense sp. nov., isolated from forest soil.

A yellow-pigmented, non-motile and rod-shaped bacterium, designated RJ-7-14T was obtained from forest soil sampled at Cheonji-dong, Seogwipo-si, Jeju-do, South Korea. Cells were Gram-stain-negative and produced flexirubin type pigments. A phylogenetic analysis based on its 16S rRNA gene sequence revealed that strain RJ-7-14T formed a lineage within the family Weeksellaceae and clustered as members of the genus Chryseobacterium. The closest members were Chryseobacterium geocarposphaerae DSM 27617T (98.2% sequence similarity), Chryseobacterium hispalense DSM 25574T (98.0%) and Chryseobacterium nepalense KACC 18907T (98.0%). The sequence similarity for other members was < 98.0%. The genome was 4,276,416 bp long with 9 scaffolds and 3779 protein-coding genes. The sole respiratory quinone was MK-6. The major cellular fatty acids were iso-C15:0, summed feature 9 (iso-C17:1 ω9c and/or C16:0 10-methyl), summed feature 3 (iso-C15:0 2-OH and/or C16: 1ω7c) and iso-C17:0 3-OH. The major polar lipid was phosphatidylethanolamine (PE). The DNA G + C content of the type strain was 37.2 mol%. In addition, the average nucleotide identity (ANIu) and in silico DNA-DNA hybridization (dDDH) relatedness values between strain RJ-7-14T and phylogenetically closest members were ≤ 88.2% and ≤ 35.0%, respectively, which were below the threshold values of 95-96% (for ANI) and 70% (for dDDH), suggesting the allocation of novel strain to a new species. Based on genomic, chemotaxonomic, phenotypic and phylogenetic analyses, strain RJ-7-14T represents novel species in the genus Chryseobacterium, for which the name Chryseobacterium cheonjiense sp. nov. is proposed. The type strain is RJ-7-14T (= KACC 21625T = NBRC 114362T).