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-101^T, TA-R-1^T, and BL-R-1^T, 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 C_16:0, C_18:1ω9c, and anteiso-C_19:0. 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-101^T = CGMCC 1.19408^T = KCTC 49761^T), Corynebacterium stercoris sp. nov. (type strain TA-R-1^T = CGMCC 1.60014^T = KCTC 49742^T), and Corynebacterium faecium sp. nov. (type strain BL-R-1^T = KCTC 49735^T = TBRC 17331^T) 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.

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 CJ661^T (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 C_16:0, cyclo-C_17:0, summed feature 3 (C_16:1ω7c and/or C_16:1ω6c) and summed feature 8 (C_18:1ω7c and/or C_18:1ω6c). 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-2^T 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-2^T was affiliated to the genus Kaistella, with the closest species being Kaistella haifensis DSM 19056^T (97.6% 16S rRNA gene sequence similarity). The principle fatty acids were iso-C_15:0, summed feature 9 (iso-C_17:1 ω9c and/or C_16:0 10-methyl), and antiso-C_15:0. 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-2^T and K. haifensis DSM 19056^T were 22.4% and 79.3%, respectively. In addition, both dDDH and ANI values between strain DKR-2^T 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-2^T represents a novel species in the genus Kaistella, for which the name Kaistella soli sp. nov. is proposed. The type strain is DKR-2^T (=KACC 22070^T=NBRC 114725^T).

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-4-1-8^T and RP-4-7^T, 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-4-1-8^T and RP-4-7^T formed a lineage within the family Burkholderiaceae and were clustered as members of the genus Paraburkholderia. Strain G-4-1-8^T showed the highest 16S rRNA sequence similarity to Paraburkholderia monticola JC2948^T (98.1 %), while strain RP-4-7^T showed the highest similarity to Paraburkholderia metrosideri DNBP6-1^T (98.8 %). The only respiratory quinone in both strains was ubiquinone Q-8. Their principal cellular fatty acids were C_16 : 0, cyclo-C_17 : 0, summed feature 3 (iso-C_15 :0 2-OH and/or C_16 :1 ω7c) and summed feature 8 (C_18 : 1  ω7c and/or C_18 : 1  ω6c). Their major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and an unidentified aminophospholipid. The DNA G+C content of strains G-4-1-8^T and RP-4-7^T 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-4-1-8^T= KACC 21617^T=NBRC 114603^T) and Paraburkholderia polaris sp. nov. (RP-4-7^T=KACC 21621^T=NBRC 114605^T) 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-1-19^T was isolated from soil of Arctic station, Svalbard, Norway. Based on the phylogenetic analysis of its 16S rRNA gene sequence, strain RP-1-19^T formed a lineage within the family Oxalobacteraceae and clustered together within the genus Massilia. The closest members were M. violaceinigra B2^T (98.6% sequence similarity), M. eurypsychrophilia JCM 30074^T (98.3%) and M. atriviolacea SOD^T (98.1%). The only respiratory quinone was ubiquinone-8. The principal cellular fatty acids were summed feature 3 (iso-C_15:0 2-OH/C_16:1ω7c) and C_16:0. 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-1-19^T 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-1-19^T that may help in cold-adaptation. Based on these data, strain RP-1-19^T represents a novel species in the genus Massilia, for which the name Massilia polaris sp. nov. is proposed. The type strain is RP-1-19^T (= KACC 21619^T = NBRC 114359^T).

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

A bacterial strain, designated strain G-1-1-14^T, was isolated from Kyonggi University forest soil during a study of previously uncultured bacterium. The cells of strain G-1-1-14^T 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-1-1-14^T belonged to the genus Azohydromonas. The closest species of strain G-1-1-14^T 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-1-1-14^T 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-C_15:0 2-OH and/or C_16:1ω7c), C_16:0, summed feature 8 (C_18:1ω7c and/or C_18:1ω6c), and cyclo-C_17:0. 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-1-1-14^T represents a novel species within the genus Azohydromonas, for which the name Azohydromonas caseinilytica sp. nov. is proposed. The type strain is G-1-1-14^T (= KACC 21615^T = NBRC 114390^T).

Aquabacterium terrae sp. nov., isolated from soil

A yellow-colored bacterial strain, designated S2^T was isolated from soil in South Korea. Cells of strain S2^T 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 S2^T consisted of summed feature 3 (iso-C_15:0 2-OH and/or C_16:1 ω7c), C_16:0 and summed feature 8 (C_18:1 ω7c and/or C_18:1 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 S2^T is phylogenetically closest to Aquabacterium pictum W35^T (98.4% sequence similarity). The genome of strain S2^T 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 S2^T was 69.4%. The average nucleotide identity and in silico DNA-DNA hybridization values between strain S2^T and phylogenetically related taxa were ≤ 77.9 and ≤ 21.4%, and respectively. The results of genotypic and phenotypic data showed that strain S2^T 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 S2^T (= KCTC 72741 ^T = NBRC 114609 ^T).

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 JC206^T (96.3% sequence similarity). The chemotaxonomic profiles revealed the presence of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, and phosphatidylcholine as the principal polar lipids; C_16:0, C_17:0 cyclo, summed feature 3 (C_16:1ω7c and/or C_{16: 1}ω6c), and summed feature 8 (C_18:1ω7c/or C_18:1ω6c) 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).

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-1^T was isolated from oil-contaminated experimental soil in Kyonggi University. The phylogenetic analysis based on 16S rRNA gene sequence revealed, strain TW-1^T formed a lineage within the family Oxalobacteraceae and clustered as members of the genus Massilia. The closest members were M. pinisoli T33^T (98.8% sequence similarity), M. putida 6NM-7^T (98.6%), M. arvi THG-RS2O^T (98.5%), M. phosphatilytica 12-OD1^T (98.3%) and M. niastensis 5516S-1^T (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-1^T 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-1^T might produce novel antimicrobial agent. The antimicrobial assessment also showed that strain TW-1^T 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-1^T represents novel species in the genus Massilia, for which the name Massilia antibiotica sp. nov. is proposed. The type strain is TW-1^T (= KACC 21627^T = NBRC 114363^T).

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-4^T 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-4^T formed a lineage within the family Erythrobacteraceae and clustered as members of the genus Novosphingobium. The closest members of strain TW-4^T were Novosphingobium subterraneum DSM 12447^T (97.9 %, sequence similarity), Novosphingobium lubricantis KSS165-70^T (97.8 %), Novosphingobium taihuense T3-B9^T (97.8 %), Novosphingobium aromaticivorans DSM 12444^T (97.7 %), Novosphingobium flavum UCT-28^T (97.7 %), and Novosphingobium bradum STM-24^T (97.6 %). The sequence similarity for other members was ≤97.6 %. The genome of strain TW-4^T 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 (C_18 : 1  ω7c and/or C_18 : 1  ω6c), summed feature 3 (C_16 : 1  ω7c and/or C_16 : 1  ω6c), C_16 : 0 and C_14 : 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-4^T and closest members were below the threshold value for species delineation. Based on polyphasic taxonomic analyses, strain TW-4^T represents novel species in the genus Novosphingobium, for which the name Novosphingobium olei sp. nov. is proposed. The type strain is TW-4^T (=KACC 21628^T=NBRC 114364^T) 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.

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-6-1-13^T was isolated from Gwanggyo mountain forest soil. Strain G-6-1-13^T 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-6-1-13^T formed a lineage within the genus Chitinophaga that was distinct from other species of the genus. Closest member was Chitinophaga varians 10-7 W-9003^T (98.6 % sequence similarity) followed by C. eiseniae DSM 22224^T (98.4 %), C. qingshengii JN246^T (97.6 %) and C. terrae KP01^T (97.4%). The major cellular fatty acids were iso-C_15 : 0, C_16 : 1  ω5c, and summed feature 3 (iso-C_15 : 0 2-OH and/or C_16 : 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-6-1-13^T 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-6-1-13^T represents a novel species in the genus Chitinophaga, for which the name Chitinophaga fulva sp. nov. is proposed. The type strain is G-6-1-13^T (=KACC 21624^T=NBRC 114361^T).

Description of Sphingobium psychrophilum sp. nov., a cold-adapted bacterium isolated from Arctic soil

A yellow-coloured, Gram-stain-negative, non-sporulating, psychrotolerant and motile bacterium, designated AR-3-1^T, was isolated from the Arctic soil of Cambridge Bay, Nunavut, Canada. Strain AR-3-1^T could grow at 4-32 °C and pH 5.0- 11.0. Phylogenetic analysis based on its 16S rRNA gene sequence indicated that strain AR-3-1^T formed a lineage within the family Sphingomonadaceae and clustered as a member of the genus Sphingobium. The closest members within this genus were Sphingobium cupriresistens CU4^T (98.1 % sequence similarity), Sphingobium vermicomposti VC-230^T (97.6 %) and Sphingobium lactosutens DS20^T (97.5 %). The only respiratory quinone was the ubiquinone Q-10. Spermidine was the predominant polyamine. The principal cellular fatty acids were summed feature 8 (C_18 : 1  ω7c and/or C_18 : 1  ω6c), summed feature 3 (iso-C_{15  : 0} 2-OH and/or C_{16  : 1} ω7c), C_16 : 0 and C_14 : 0 2-OH. The major polar lipids were phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, sphingoglycolipid and phosphoglycolipid. The DNA G+C content was 63.1 %. The average nucleotide identity and in silico DNA-DNA hybridization relatedness values between strain AR-3-1^T and its most closely related genus members were ≤89.6 and 39.6 %, respectively. The genome was 5 162 327 bp long, with 83 scaffolds and 4824 protein-coding genes. The genome showed six putative biosynthetic gene clusters responsible for various secondary metabolites. Based on this polyphasic study, strain AR-3-1^T represents a novel species within the genus Sphingobium, for which the name Sphingobium psychrophilum sp. nov. is proposed. The type strain is AR-3-1^T (=KACC 21613^T=NBRC 114604^T).

Flexivirga aerilata sp. nov., Isolated from an Automobile Air Conditioning System

A novel light-yellow-coloured, Gram-stain-positive, nearly-coccoid, aerobic bacterium, designated strain ID2601S^T was isolated from a car evaporator core collected from South Korea. Strain ID2601S^T was catalase positive and oxidase negative, able to grow at pH 6.0-8.0, temperature 20-45 °C, and 0-6.0% (w/v) NaCl concentration. The 16S rRNA gene sequence analysis showed that strain ID2601S^T belonged to the genus Flexivirga, with the nearest phylogenetic neighbour being Flexivirga endophytica YIM 7505^T (97.9% sequence similarity). The strain comprised diphosphatidylglycerol as the main polar lipid; MK-8(H₄) as a predominant respiratory quinone; serine, alanine, glycine, glutamic acid, and lysine as main components of peptidoglycan and iso-C_16:0, summed feature 9 (iso-C_17:1ω9c and/or C_16:0 10-methyl), anteiso-C_17:0, and C_17:0 10-methyl as the major fatty acids. The average nucleotide identity (ANI) values between strain ID2601S^T and the closest species (Flexivirga endophytica YIM 7505^T and Flexivirga caeni BO-16^T) were < 78%. The in silico DNA-DNA hybridization (dDDH) values of strain ID2601S^T with the closest species were < 22%. These observations were below the threshold values of 95% (for ANI) and 70% (for dDDH) used for species delineation. The DNA G+C content was 69.8 mol%. Based on the polyphasic taxonomic data, the novel species Flexivirga aerilata sp. nov. is proposed with the type strain ID2601S^T (=KCTC 49353^T =NBRC 114622^T).

Caenimonas soli sp. nov., isolated from soil

A non-motile, Gram-stain-negative, rod-shaped bacterium, designated strain S4^T, was obtained from soil sampled at Wonju, Gyeonggi-do, Republic of Korea. Cells were white-coloured, aerobic, grew optimally at 25-32 °C on R2A agar plate. A phylogenetic analysis based on its 16S rRNA gene sequence revealed that strain S4^T formed a lineage within the family Comamonadaceae. The closest members were Caenimonas terrae SGM1-15^T (98.1% sequence similarity), Caenimonas koreensis EMB320^T (97.5%) and Ramlibacter solisilvae 5-10^T (97.8%). The sequence similarities of strain S4^T with other members of the family Comamonadaceae were ≤ 97.5%. The sole respiratory quinone was ubiquinone-8 (Q-8) and the principal polar lipid was phosphatidylethanolamine. The predominant cellular fatty acids were summed feature 3 (iso-C_15 :0 2-OH/C_16 :1 ω7c), C_16:0 and summed feature 8 (C_18:1 ω7c and/or C_18:1 ω6c). The DNA G + C content was 65.1 mol%. In addition, the average nucleotide identity (ANIu) and in silico DNA-DNA hybridization (dDDH) relatedness values between strain S4^T and Caenimonas koreensis were 77.6 and 21%, respectively. Based on genomic, chemotaxonomic, phenotypic, and phylogenetic analyses, strain S4^T represents a novel species in the genus Caenimonas, for which the name Caenimonas soli sp. nov. is proposed. The type strain is S4^T (= KCTC 72742^T = NBRC 114610^T).

Luteolibacter luteus sp. nov., isolated from stream bank soil

A non-motile, Gram-stain-negative, rod-shaped and yellow-colored bacterium, designated G-1-1-1^T was obtained from soil sampled at Gwanggyo stream bank, Gyeonggi-do, Republic of Korea. Cells were aerobic, catalase positive, grew optimally at 25-30 °C and hydrolysed aesculin and casein. A phylogenetic analysis based on its 16S rRNA gene sequence revealed that strain G-1-1-1^T formed a lineage within the genus Luteolibacter. The closest members were Luteolibacter flavescens GKX^T (97.7% sequence similarity) and Luteolibacter arcticus MC 3726^T (97.3%). The sequence similarities with other members of the genus Luteolibacter were ≤ 93.9%. The genome of strain G-1-1-1^T was 6,412,079 bp long with 5176 protein-coding genes. The diagnostic amino acid of cell-wall peptidoglycan of strain G-1-1-1^T was meso-diaminopimelic acid. The only respiratory quinone was menaquinone-9 and the principal polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and unidentified phospholipids. The predominant cellular fatty acids were iso-C_14:0, C_16:1 ω9c, C_16:0, C_14:0 and anteiso-C_15:0. The DNA G + C content was 61.0 mol%. The anti-SMASH analysis of whole genome showed eight putative biosynthetic gene clusters responsible for various secondary metabolites. Based on genomic, chemotaxonomic, phenotypic and phylogenetic analyses, strain G-1-1-1^T represents a novel species in the genus Luteobacter, for which the name Luteolibacter luteus sp. nov. is proposed. The type strain is G-1-1-1^T (= KACC 21614^T = NBRC 114341^T).

Zoogloea dura sp. nov., a N2-fixing bacterium isolated from forest soil and emendation of the genus Zoogloea and the species Zoogloea oryzae and Zoogloea ramigera

A motile, Gram-stain-negative, rod-shaped bacterium, designated G-4-1-14^T, was obtained from forest soil sampled at Gwanggyo mountain, Gyeonggi-do, Republic of Korea. Cells were colourless, aerobic, grew optimally at 28-35 °C and hydrolysed DNA and casein. Phylogenetic analysis based on its 16S rRNA gene sequence revealed that strain G-4-1-14^T formed a lineage within the genus Zoogloea. The closest members were Zoogloea resiniphila ATCC 70068^T (98.6 % sequence similarity), Zoogloea caeni EMB43^T (98.2 %), Zoogloea oryzae A-7^T (97.7 %), Zoogloea ramigera IAM 12136^T (96.9 %) and Zoogloea oleivorans Buc^T (96.2 %). The major respiratory quinone was ubiquinone-8 and the principal polar lipids were phosphatidylethanolamine, phosphatidyl-N-methylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The predominant cellular fatty acids were summed feature 3 (iso-C_15 :0 2-OH/C_{16  : 1} ω7c) and C_16 : 0. The DNA G+C content was 65.9 mol%. The average nucleotide identity and digital DNA-DNA hybridization relatedness values between strain G-4-1-14^T and other type strains were ≤81.6 and ≤24.9 %, respectively, which are below the species demarcation thresholds. Based on the results of phenotypic, phylogenetic and genomic analyses, strain G-4-1-14^T represents a novel species in the genus Zoogloea, for which the name Zoogloea dura sp. nov. is proposed. The type strain is G-4-1-14^T (=KACC 21618^T=NBRC 114358^T). In addition, we propose emendation of the genus Zoogloea and the species Zoogloea oryzae and Zoogloea ramigera.

Hymenobacter polaris sp. nov., a psychrotolerant bacterium isolated from an Arctic station

A pink-pigmented, non-motile, Gram-stain-negative, rod-shaped bacterium, designated RP-2-7^T, was obtained from soil sampled at the Arctic station, Spitsbergen, Svalbard, Norway. Cells were strictly aerobic, psychrotolerant, grew optimally at 15-20 °C and hydrolysed CM-cellulose. Phylogenetic analysis based on its 16S rRNA gene sequence revealed that strain RP-2-7^T formed a lineage within the family Hymenobacteraceae and clustered with members of the genus Hymenobacter. Its closest relative was Hymenobacter marinus KJ035^T (97.6 % sequence similarity). The sequence similarities to other strains were ≤96.9 %. The principal respiratory quinone was MK-7 and the major polar lipids were phosphatidylethanolamine and an unidentified aminophospholipid. The predominant cellular fatty acids were summed feature 3 (C_16 : 1  ω7c and/or C_16 : 1  ω6c), anteiso-C_15 : 0, iso-C_15 : 0, C_16 : 1  ω5c and summed featured 4 (iso-C_17 : 1 I and/or anteiso-C_17 : 1 B). The DNA G+C content was 62.8 mol%. In addition, the average nucleotide identity and in silico DNA-DNA hybridization relatedness values between strain RP-2-7^T and closely related strains were lower than species demarcation thresholds. Based on the resuls of genomic, chemotaxonomic, phenotypic and phylogenetic analyses, strain RP-2-7^T represents novel species in the genus Hymenobacter, for which the name Hymenobacter polaris sp. nov. is proposed. The type strain is RP-2-7^T (=KACC 21670^T=NBRC 114391^T).

Flavobacterium sandaracinum sp. nov., Flavobacterium caseinilyticum sp. nov., and Flavobacterium hiemivividum sp. nov., novel psychrophilic bacteria isolated from Arctic soil

This study presents taxonomic description of strains LB-D12T, AT-3-2T, AT-3–7, and TSA-D2T isolated from Arctic soil. All strains were psychrophilic, Gram-stain-negative, aerobic, non-motile, and rod-shaped. Phylogenetic analysis showed that these strains belonged to the genus Flavobacterium . Strains LB-D12T, AT-3-2T and AT-3–7 were closest to Flavobacterium psychrolimnae LMG 22018T (98.5–98.8% sequence similarity). Strain TSA-D2T was closest to Flavobacterium degerlachei DSM 15718T (98.3 % sequence similarity). These strains shared common chemotaxonomic features comprising MK-6 as a sole quinone, phosphatidylethanolamine as the principal polar lipid, and summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c), iso-C16 : 0 3-OH, C15 : 1ω6c, iso-C16 : 0, and anteiso-C15 : 0 as the main fatty acids. The ANI and dDDH values between these novel isolates and their closest relatives were below the cut-off values of 95 and 70 %, respectively used for species demarcation. The DNA G+C content of all strains ranged from 34.2 to 34.6 mol%. The obtained polyphasic taxonomic data suggested that the isolated strains represent novel species within the genus Flavobacterium , for which the names Flavobacterium sandaracinum sp. nov. (type strain LB-D12T=KEMB 9005-737T=KACC 21180T=NBRC 113784T), Flavobacterium caseinilyticum sp. nov. (type strain AT-3–2T=KEMB 9005-738T=KACC 21176T=NBRC 113785T), and Flavobacterium hiemivividum sp. nov. (type strain TSA-D2T=KEMB 9005-741T=KACC 21179T=NBRC 113788T) are proposed.

Nine novel psychrotolerant species of the genus Pedobacter isolated from Arctic soil with potential antioxidant activities

Fifteen isolates of the genus Pedobacter were obtained from Arctic soil samples. All isolates were Gram-stain-negative and rod-shaped. Cells were strictly aerobic, psychrotolerant and grew optimally at 15–20 °C. Phylogenetic analysis based on 16S rRNA gene sequences revealed that all the isolated strains formed a lineage within the family Sphingobacteriaceae and clustered as members of the genus Pedobacter . The sole respiratory quinone was MK-7 and the major polar lipid was phosphatidylethanolamine. The major cellular fatty acids were summed feature 3 (iso-C15 : 02-OH/C16 : 1ω7c/ω6c), iso-C15 : 0 and iso-C17 : 0 3-OH. The DNA G+C content of the novel strains was 33.9–41.8 mol%. In addition, the average nucleotide identity and in silico DNA–DNA hybridization relatedness values between the novel type strains and phylogenetically related type strains were below the threshold values used for species delineation. Based on genomic, chemotaxonomic, phenotypic, phylogenetic and phylogenomic analyses, the isolated strains represent novel species in the genus Pedobacter , for which the names Pedobacter cryotolerans sp. nov. (type strain AR-2-6T=KEMB 9005-717T=KACC 19998T=NBRC 113826T), Pedobacter cryophilus sp. nov. (type strain AR-3-17T=KEMB 9005-718T=KACC 19999T=NBRC 113827T), Pedobacter frigiditerrae sp. nov. (type strain RP-1-13T=KEMB 9005-720T=KACC 21147T=NBRC 113829T), Pedobacter psychroterrae sp. nov. (type strain RP-1-14T=KEMB 9005-721T=KACC 21148T=NBRC 113830T), Pedobacter hiemivivus sp. nov. (type strain RP-3-8T=KEMB 9005-724T=KACC 21152T=NBRC 113833T), Pedobacter frigidisoli sp. nov. (type strain RP-3-11T=KEMB 9005-725T=KACC 21153T=NBRC 113927T), Pedobacter frigoris sp. nov. (type strain RP-3-15T=KEMB 9005-726T=KACC 21154T=NBRC 113834T), Pedobacter psychrodurus sp. nov. (type strain RP-3-21T=KEMB 9005-728T=KACC 21156T=NBRC 113835T) and Pedobacter polaris sp. nov. (type strain RP-3-22T=KEMB 9005-729T=KACC 21157T=NBRC 113836T) are proposed.

Flavobacterium silvisoli sp. nov., isolated from forest soil

During a study of the Kyonggi University soil bacterial diversity, an aerobic, non-motile, Gram-stain-negative, non-spore-forming, rod-shaped, yellow pigmented bacterium, designated strain RD-2-33^T was isolated. Strain RD-2-33^T grew optimally at 28-35 °C and pH 7.0-7.5; hydrolysed gelatin and DNA; and tolerated 1 % of NaCl. A phylogenetic analysis based on its 16S rRNA gene sequence revealed that strain RD-2-33^T clustered with the genus Flavobacterium. The closest member was Flavobacterium dankookense ARSA-19^T (97.1 % sequence similarity) and Flavobacterium cheonhonense ARSA-15^T (96.7 %). Sole respiratory quinone was MK-6. The major polar lipids were phosphatidylethanolamine and an unidentified polar lipid. The major cellular fatty acids were iso-C_15 : 0, iso-C_17 : 0 3-OH, and iso-C_15 : 1 G. The DNA G+C content was 38.6 mol%. The average nucleotide identity (ANI) and in silico DNA-DNA hybridisation relatedness between strain RD-2-33^T and Flavobacterium dankookense DSM 25687^T were 75.2 and 19.3 %, respectively. Based on the polyphasic and phylogenetic data, strain RD-2-33^T represents a novel species of the genus Flavobacterium, for which the name Flavobacterium silvisoli sp. nov. is proposed. The type strain is RD-2-33^T (=KEMB 9005-742^T=KACC 21178^T=NBRC 113789^T).

Rhodanobacter hydrolyticus sp. nov., a novel DNA- and tyrosine-hydrolysing gammaproteobacterium isolated from forest soil

A bacterial isolate, designated G-5-5^T, was isolated from forest soil at Kyonggi University. Strain G-5-5^T was acid-tolerant and alkali-tolerant. Cells were strictly aerobic, Gram-stain-negative, catalase- and oxidase-positive, non-motile, non-spore-forming, rod-shaped, and yellow-coloured. Strain G-5-5^T hydrolysed DNA and tyrosine; assimilated d-glucose, maltose, N-acetyl-glucosamine and l-fucose; and tolerated only 0.5 % NaCl (w/v). Phylogenetic analysis based on its 16S rRNA gene sequence revealed that strain G-5-5^T formed a lineage within the family Rhodanobacteraceae and that it grouped with but was distinct from various members of the genus Rhodanobacter. The closest member was Rhodanobacter umsongensis GR24-2^T (97.8 % sequence similarity). The sole respiratory quinone was Q-8. The major polar lipids of strain G-5-5^T were phosphatidylethanolamine, phosphatidyl-N-methylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The major cellular fatty acids were summed feature 9 (iso-C17 : 1ω9c and/or C16 : 0 10-methyl), iso-C15 : 0, iso-C17 : 0, iso-C16 : 0 and anteiso-C15 : 0. The DNA G+C content of strain G-5-5^T was 64.1 mol%. DNA-DNA hybridization relatedness between strain G-5-5^T and other close members of the genus Rhodanobacter ranged from 19 % to 45 %. On the basis of the polyphasic characterization and phylogenetic analyses, strain G-5-5^T represents a novel species of the genus Rhodanobacter, for which the name Rhodanobacter hydrolyticus sp. nov. is proposed. The type strain is G-5-5^T (=KEMB 9005-533^T=KACC 19113^T=NBRC 112685^T).

Sphingomonas montis sp. nov., Isolated from Forest Soil of Low-Altitude Mountain

Strain DRJ-4^T was isolated from forest soil of a low-altitude mountain and was taxonomically characterized by a polyphasic approach. This strain was yellow-colored, Gram-stain-negative, strictly aerobic, motile, non-sporulating, catalase-positive, oxidase-negative, and rod-shaped. Strain DRJ-4^T was able to grow at 20-42 °C, pH 6.5-10.0, and 0-1.0% (w/v) NaCl concentration. Based on the 16S rRNA gene sequence analysis, strain DRJ-4^T formed a distinct lineage within the members of the family Sphingomonadaceae of the phylum Proteobacteria and moderately related to Sphingomonas faucium E62-3^T (96.67% sequence similarity), 'Sphingosinicella ginsenosidimutans' BS11 (96.45% sequence similarity), Sphingosinicella vermicomposti YC7378^T (96.27% sequence similarity), and Sphingobium boeckii 469^T (95.82% sequence similarity). The sole respiratory quinone was ubiquinone Q-10 and the major polyamine was homospermidine. The polar lipid profile revealed the presence of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine, phosphatidylmonomethylethanolamine, and sphingoglycolipid. The predominant fatty acids of strain DRJ-4^T were summed feature 8 (C_18:1ω7c and/or C_18:1ω6c), summed feature 3 (C_16:1ω7c and/or C_16:1ω6c), C_16:0, and C_17:1ω6c. The genomic DNA G + C was 64.0 mol %. On the basis of phenotypic, genotypic, and phylogenetic analysis, strain DRJ-4^T represents a novel species of the genus Sphingomonas, for which the name Sphingomonas montis sp. nov. is proposed. The type strain of Sphingomonas montis is DRJ-4^T (= KEMB 9005-708^T = NBRC 113142^T).

Pinisolibacter ravus gen. nov., sp. nov., isolated from pine forest soil and allocation of the genera Ancalomicrobium and Pinisolibacter to the family Ancalomicrobiaceae fam. nov., and emendation of the genus Ancalomicrobium Staley 1968

A novel bacterium, designated strain E9^T, was isolated from pine forest soil of Kyonggi University (Suwon, Republic of Korea). Cells were facultatively anaerobic, Gram-staining-negative, catalase-negative, oxidase-positive, non-motile, non-spore-forming, rod-shaped and straw coloured. Prosthecae were absent. Glucose was fermented. The strain grew in the pH range of 5.0-10.0 (optimum, 6.5-8.5) and at 45 °C (optimum, 28-32 °C). E9^T was sensitive to NaCl at low concentration and tolerated only 0.2 % NaCl (w/v). A phylogenetic analysis based on 16S rRNA gene sequences revealed that E9^T formed a lineage within the phylum Proteobacteria that was distinct from various members of the order Rhizobiales, including Ancalomicrobium adetum DSM 4722^T (94.76 % sequence similarity), 'Nitratireductor lucknowense' IITR-21 (92.72 %), Prosthecomicrobium hirschii 16^T (92.66 %) and Kaistia soli DSM 19436^T (92.53 %). The predominant isoprenoid quinone was Q-10. The major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and phosphatidyl-N-methylethanolamine. Major cellular fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), and C16 : 0. The DNA G+C content of the type strain was 68.4 mol%. Polyphasic characterization indicated that strain E9^T represented a novel species in a novel genus within a novel family, for which the name Pinisolibacter ravus gen. nov., sp. nov. is proposed. The type strain of Pinisolibacter ravus is E9^T (=KEMB 9005-534^T=KACC 19120^T=NBRC 112686^T). A formal allocation of the genus Ancalomicrobium to the family Ancalomicrobiaceae fam. nov. is also proposed.

Fluviicola kyonggii sp. nov., a bacterium isolated from forest soil and emended description of the genus Fluviicola

A novel bacterium, designated strain CA-1^T, was isolated from forest soil in Kyonggi University. Cells were strictly aerobic, Gram-stain-negative, catalase-positive, oxidase-negative, non-motile, non-spore-forming, rod-shaped and red-orange-pigmented. Strain CA-1^T hydrolysed casein and DNA. It was able to grow at 15-37 °C, pH 5.5-9.0 and at 0-2 % (w/v) NaCl concentration. Flexirubin-type pigments were present. Phylogenetic analysis based on its 16S rRNA gene sequence indicated that strain CA-1^T formed a lineage within the family Crocinitomicaceae of the phylum Bacteroidetes that was distinct from Fluviicola hefeinensis MYL-8^T (96.8 % sequence similarity) and Fluviicola taffensis DSM 16823^T (96.1 %). Strain CA-1^T contained menaquinone-6 as a sole respiratory quinone. The major polar lipids were phosphatidylethanolamine, unidentified aminolipids, an unidentified aminophospholipid and an unidentified lipid. The major cellular fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH, C15 : 0 2-OH, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and iso-C15 : 1 G. The DNA G+C content of strain CA-1^T was 44.1 mol%. The polyphasic characterization revealed that strain CA-1^T represents a novel species in the genus Fluviicola, for which the name Fluviicola kyonggii sp. nov. is proposed. The type strain is CA-1^T (=KEMB 9005-526^T=KACC 19148^T=NBRC 112684^T).

Proposal of Nemorincola gen. nov. to replace the illegitimate prokaryotic genus name Nemorella Chaudhary et al. 2018

The prokaryotic genus name Nemorella Chaudhary et al. 2018 is illegitimate because it is a later homonym of the plant genus name Nemorella Ehrhart 1789 [Principle 2 of the Prokaryotic Code (2008 Revision)]. This name is therefore not a correct name (Principle 6). Based on Rule 54 we propose the replacement name Nemorincola with Nemorincola caseinilytica as the type species.

Brevundimonas humi sp. nov., an alphaproteobacterium isolated from forest soil

During a study of bacterial diversity of soil, a novel strain, CA-15^T, was isolated from Kyonggi University forest soil. Cells were aerobic, Gram-stain-negative, motile, non-spore-forming, rod-shaped, oxidase-positive and catalase- negative. Tyrosine was not oxidized but produced red pigmentation on an agar palte. Strain CA-15^T hydrolysed Tween 60 and DNA. It grew at 15-35 °C (optimum, 25-30 °C), pH 6.0-10.0 (optimum, 7.0-9.0) and at 1.5 % (w/v) NaCl concentration. Phylogenetic analysis based on its 16S rRNA gene sequence indicated that strain CA-15^T formed a lineage within the family Caulobacteraceae of the class Alphaproteobacteria that was distinct from various species of the genus Brevundimonas. Brevundimonas bullata DSM 7126^T was the closest member of strain CA-15^T on the basis of 16S rRNA gene sequence similarity (98.48 %). Q-10 was only an isoprenoid quinone detected for strain CA-15^T. The major polar lipids were 1,2-di-O-acyl-3-O-[d-glucopyranosyl-(1→4)-αd-glucopyranuronosyl]glycerol, 1,2-di-O-acyl-3-O-[αd-glucopyranosyl]-sn-glycerol, 1,2-di-O-acyl-3-O-αd-glucopyranuronosylglycerol, 1,2-diacyl-3-O-[6'-phosphatidyl-αd-glucopyranosyl]glycerol and phosphatidylglycerol. The major cellular fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), C16 : 0, C18 : 1ω7c 11-methyl and C17 : 1ω8c. The DNA G+C content of strain CA-15^T was 63.6 mol%. The polyphasic characterization indicated that strain CA-15^T represents a novel species in the genus Brevundimonas, for which the name Brevundimonas humi sp. nov. is proposed. The type strain of Brevundimonas humi is CA-15^T (=KEMB 9005-528^T=KACC 19106^T=NBRC 112677^T).

Ferrovibrio soli sp. nov., a novel cellulolytic bacterium isolated from stream bank soil

Two isolates of bacterial strains A15^T and A17 were isolated from stream bank soil in Kyonggi University. Cells were aerobic, Gram-stain-negative, oxidase- and catalase-positive, motile, non-spore-forming, rod-shaped, opaque, and cream coloured. Both strains hydrolysed CM-cellulose. Strains were able to grow at 20-42 °C, pH 5.5-10.0 and at 1.5 % NaCl concentration (w/v). Indole test was positive. Analyses of phylogenetic trees based on its 16S rRNA gene sequences indicated that strain A15^T formed a lineage within the family Rhodospirillaceae of the phylum Proteobacteria which was distinct from Ferrovibrio denitrificans S3^T (98.4 % sequence similarity) and Ferrovibrio xuzhouensis LM-6^T (97.4 %). The sole detected respiratory quinone was Q-10. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and an unidentified aminolipid. The major cellular fatty acids were C19 : 0 cycloω8c, C16 : 0, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), C18 : 0cyclo and C12 : 0. The DNA G+C contents of strains A15^T and A17 were 63.4 and 62.9 mol%, respectively. DNA-DNA relatedness between strain A15^T and other two members of the genus Ferrovibrioranged from 25 to 37 %. The polyphasic characterization revealed strains A15^T and A17 represent a novel species in the genus Ferrovibrio, for which the name Ferrovibriosoli sp. nov. is proposed. The type strain is A15^T (=KEMB 9005-522^T=KACC 19102^T=NBRC 112682^T).

Nemorella caseinilytica gen. nov., sp. nov., isolated from forest soil

Two novel strains, J116-2^T and J116-1, were isolated from forest soil and were taxonomically characterized by a polyphasic approach. Both strains were yellow-coloured, Gram-stain-negative, strictly aerobic, non-motile and rod-shaped bacteria. The strains were non-sporulating, catalase-positive and oxidase-negative. Strains J116-2^T and J116-1 were able to grow at 20-32 °C, pH 6.0-8.5, and 0-0.5 % (w/v) NaCl concentration. Based on 16S rRNA gene sequence analyses, strains J116-2^T and J116-1 formed a distinct lineage within the family Chitinophagaceae of the phylum Bacteroidetes and were closely related to genera Taibaiella (89.86-89.30 % sequence similarity), Falvihumibacter (89.20-89.06 %), Filimonas (89.06 %) and Chitinophaga(89.01-88.77 %). The pairwise sequence similarity between strains J116-2^T and J116-1 was found to be 99.86 %. Flexirubin-type pigments were absent in both strains. The only respiratory quinone was menaquinone-7 (MK-7); the major polar lipid was phosphatidylethanolamine; the predominant polyamine was homospermidine; and the major fatty acids were C15 : 0iso, C15 : 1iso G and C17 : 0iso 3-OH. The genomic DNA G+C content values of strains J116-2^T and J116-1 were 51.1 and 50.9 mol%, respectively. On the basis of phenotypic, genotypic and phylogenetic analysis, strain J116-2^T represents a novel species of a new genus in the family Chitinophagaceae, for which the name Nemorella caseinilytica gen. nov., sp. nov. is proposed. The type strain of Nemorella caseinilytica is J116-2^T (=KEMB 9005-550^T=KACC 19168^T=NBRC 112827^T).

Ravibacter arvi gen. nov., sp. nov., isolated from farmland soil during development of new culture techniques

Two novel strains, J77-1^T and J76-1, were isolated from farmland soil and were taxonomically characterized by a polyphasic approach. Both strains were yellow, Gram-stain-negative, strictly aerobic, non-motile and rod-shaped bacteria. These strains were non-sporulating, catalase-positive and oxidase-negative. J77-1^T and J76-1 were able to grow at 15-40 °C, pH 5.0-10.0, and 0-1.0 % (w/v) NaCl concentration. Phylogenetic analyses revealed that both strains formed a distinct separate lineage within the family Cytophagaceae of the phylum Bacteroidetes. J77-1^T and J76-1 showed low 16S rRNA gene sequence similarity to the most closely related type strain Dyadobacter koreensis WPCB159^T (85.09 %) and exhibited less than 85.0 % sequence similarity with other members of the family Cytophagaceae. The pairwise sequence similarity between strains J77-1^T and J76-1 was observed to be 99.86 %. In both strains, the only respiratory quinone was menaquinone-7 (MK-7); the major polar lipid was phosphatidylethanolamine; and the major fatty acids were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0, iso-C15 : 0, iso-C17 : 0 3-OH C16 : 1ω5c, and C16 : 0 3-OH. The genomic DNA G+C content values of J77-1^T and J76-1 were 50.1 and 50.9 mol%, respectively. On the basis of the results of phenotypic, genotypic and phylogenetic analysis, J77-1^T represents a novel species of a novel genus, for which the name Ravibacter arvi gen. nov., sp. nov. is proposed, within the family Cytophagaceae. The type strain of Ravibacter arvi is J77-1^T (=KEMB 9005-548^T=KACC 19172^T=JCM 31920^T), and J76-1 is an additional strain.

Calidifontibacter terrae sp. nov., an actinomycete isolated from soil, with potential applications in cosmetics

An aerobic, Gram-stain-positive, oxidase- and catalase-positive, non-motile, non-spore-forming, coccoid, creamish-white-coloured bacterium, designated strain R161T, was isolated from soil in Hwaseong, South Korea. The cell-wall peptidoglycan contained glycine, glutamic acid, alanine, aspartic acid, serine and lysine, and whole-cell sugars were galactose, rhamnose, glucose and ribose. Strain R161T showed antibacterial and enzyme inhibitory activities. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain R161T formed a lineage within the family Dermacoccaceae, and showed highest sequence similarity with type strains of Calidifontibacter indicus PC IW02T (97.71 % sequence similarity) and Yimella lutea YIM 45900T (97.58 %). The sequence similarity of strain R161T with type strains of members of the genus Dermacoccus was less than 96.5 %. The major menaquinone was MK-8(H4). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannosides. The major cellular fatty acids were iso-C16 : 0, anteiso-C17 : 0, iso-C16 : 1 H, anteiso-C17 : 1ω9c, summed feature 9 (iso-C17 : 1ω9c and/or C16 : 0 10-methyl) and iso-C15 : 0. The DNA G+C content of strain R161T was 73.9 mol%. The DNA-DNA hybridization value between strain R161T and C. indicus JCM 16038T was 52.1 %. On the basis of phenotypic, genotypic, chemotaxonomic and phylogenetic analysis, strain R161T represents a novel species of genus Calidifontibacter, for which the name Calidifontibacter terrae sp. nov. is proposed. The type strain of Calidifontibacter terrae sp. nov. is R161T (=KEMB 9005-404T=KACC 18906T=JCM 31558T).

Niabellapedocola sp. nov., isolated from soil

An aerobic, Gram-stain-negative, oxidase-positive and catalase-negative, non-motile, non-spore-forming, rod-shaped, orange-pigmented bacterium designated strain R384^T was isolated from soil. Flexirubin-type pigments were present. Phylogenetic analysis based on its 16S rRNA gene sequence revealed that strain R384^T formed a lineage within the family Chitinophagaceae of the phylum Bacteroidetes that was distinct from various species of the genus Niabella, including 'Niabella thaonhiensis' NHI-24 (98.47 % sequence similarity), Niabellaaurantiaca DSM 17617^T (96.89 %), Niabelladrilacis E90^T (96.63 %), Niabellahirudinis E96^T (96.61 %), Niabellatibetensis 15-4^T (95.53 %), Niabellasoli DSM 19437^T (94.81 %), Niabellaginsengisoli GR10-1^T (94.19 %) and Niabellayanshanensis CCBAU 05354^T (93.67 %). The major isoprenoid quinone was menaquinone-7 (MK-7) and the major polar lipid was phosphatidylethanolamine. The major cellular fatty acids were iso-C15 : 0, iso-C15 : 1 G, summed feature 3 (C16 : 1ω7c/C16 : 1ω6c) and iso-C17 : 0 3-OH. The DNA G+C content of strain R384^Twas 44.7 mol %. DNA-DNA hybridization values between strain R384^T and other members of the genus Niabella ranged from 26 to 55 %. On the basis of phenotypic, genotypic and phylogenetic analysis, strain R384^T represents a novel species of the genus Niabella, for which the name Niabellapedocola sp. nov. is proposed. The type strain is R384^T (=KEMB 9005-329^T=KACC 18454^T=JCM 31011^T).