Decoding and overcoming T cell exhaustion: Epigenetic and transcriptional dynamics in CAR-T cells against solid tumors.

T cell exhaustion, which is observed in various chronic infections and malignancies, is characterized by elevated expression of multiple inhibitory receptors, impaired effector functions, decreased proliferation, and reduced cytokine production. Notably, while adoptive T cell therapies, such as chimeric antigen receptor (CAR)-T therapy, have shown promise in treating cancer and other diseases, the efficacy of these therapies is often compromised by T cell exhaustion. It is imperative, therefore, to understand the mechanisms underlying this exhaustion to promote advances in T cell-related therapies. Here, we divided exhausted T cells into three distinct subsets according to their developmental and functional profiles: stem-like progenitor cells, intermediately exhausted cells, and terminally exhausted cells. These subsets are carefully regulated by synergistic mechanisms that involve transcriptional and epigenetic modulators. Key transcription factors, such as TCF1, BACH2, and TOX, are crucial for defining and sustaining exhaustion phenotypes. Concurrently, epigenetic regulators, such as TET2 and DNMT3A, shape the chromatin dynamics that direct T cell fate. The interplay of these molecular drivers has recently been highlighted in CAR-T research, revealing promising therapeutic directions. Thus, a profound understanding of exhausted T cell hierarchies and their molecular complexities may reveal innovative and improved tumor treatment strategies.

Role of TRPC3 in Right Ventricular Dilatation under Chronic Intermittent Hypoxia in 129/SvEv Mice.

Patients with obstructive sleep apnea (OSA) exhibit a high prevalence of pulmonary hypertension and right ventricular (RV) hypertrophy. However, the exact molecule responsible for the pathogenesis remains unknown. Given the resistance to RV dilation observed in transient receptor potential canonical 3(Trpc3)-/- mice during a pulmonary hypertension model induced by phenylephrine (PE), we hypothesized that TRPC3 also plays a role in chronic intermittent hypoxia (CIH) conditions, which lead to RV dilation and dysfunction. To test this, we established an OSA mouse model using 8- to 12-week-old 129/SvEv wild-type and Trpc3-/- mice in a customized breeding chamber that simulated sleep and oxygen cycles. Functional parameters of the RV were evaluated through analysis of cardiac cine magnetic resonance images, while histopathological examinations were conducted on cardiomyocytes and pulmonary vessels. Following exposure to 4 weeks of CIH, Trpc3-/- mice exhibited significant RV dysfunction, characterized by decreased ejection fraction, increased end-diastole RV wall thickness, and elevated expression of pathological cardiac markers. In addition, reactive oxygen species (ROS) signaling and the endothelin system were markedly increased solely in the hearts of CIH-exposed Trpc3-/- mice. Notably, no significant differences in pulmonary vessel thickness or the endothelin system were observed in the lungs of wild-type (WT) and Trpc3-/- mice subjected to 4 weeks of CIH. In conclusion, our findings suggest that TRPC3 serves as a regulator of RV resistance in response to pressure from the pulmonary vasculature, as evidenced by the high susceptibility to RV dilation in Trpc3-/- mice without notable changes in pulmonary vasculature under CIH conditions.

Paludirhabdus telluriireducens gen. nov., sp. nov. and Paludirhabdus pumila sp. nov., isolated from soil of a mountain wetland and emended description of Gorillibacterium massiliense.

Two strains of Gram-stain-positive, endospore-forming, motile by means of peritrichous flagella, aerobic or facultative anaerobic, and rod-shaped bacteria that were designated ON8T and ON6T were isolated from soil collected from a mountain wetland in Gwang-ju, Republic of Korea. The isolates were catalase-positive and oxidase-negative. Cells of ON8T and ON6T grew at 15-35 °C (optimal 30 °C) and 15-40 °C (optimal 30 °C), respectively. The major menaquinone was MK-7 and the major cellular fatty acids (>10 % of the total) were anteiso-C15 : 0, iso-C15 : 0, C14 : 0 and C16 : 0. The predominant polar lipids were diphosphatidylglycerol, aminophospholipid and phospholipid. Meso-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan. The DNA G+C contents of strains ON8T and ON6T were 50.6 and 53.5 mol%, respectively, and the 16S rRNA gene sequence analysis showed that the nearest phylogenetic neighbour of both strains was Gorillibacterium massiliense G5T (93.9 %), followed by the members of the genus Paenibacillus in the family Paenibacillaceae. The DNA-DNA hybridization relatedness value between ON8T and ON6T was 44.1 %, which indicated that they represented distinct species. Based on polyphasic characteristics, a novel genus is proposed with the name Paludirhabdus gen. nov., which consists of two species, Paludirhabdus telluriireducens sp. nov. (the type species; type strain ON8T=KACC 19267T=JCM 31958T) and Paludirhabdus pumila sp. nov. (type strain ON6T=KACC 19266T=JCM 31957T).

Uliginosibacterium sediminicola sp. nov., isolated from freshwater sediment.

Strain M1-21T is a Gram-stain-negative, strictly aerobic and short-rod-shaped bacterium, motile by means of a single polar flagellum; it was isolated from freshwater sediment in Korea. It grew at 10-40 °C (optimum 25 °C), pH 6.0-8.0 (optimum pH 7.0) and with 0-0.75 % (w/v) NaCl (optimal growth occurred in the absence of NaCl) on R2A agar, and it accumulated poly-ß-hydroxybutyrate granules inside the cells. According to 16S rRNA gene sequence analysis, strain M1-21T showed highest sequence similarity with Uliginosibacterium gangwonense (94.7 %) and Uliginosibacterium paludis (94.4 %). Phylogenetic analysis of the 16S rRNA gene sequences revealed that strain M1-21T belongs to the genus Uliginosibacterium. The DNA G+C content of strain M1-21T was 61.9 mol%. The predominant respiratory quinone was ubiquinone-8. The major fatty acids (>10 % of the total) were C16 : 0 and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Strain M1-21T showed distinct phenotypic characteristics that differentiated it from species of the genus Uliginosibacterium. Based on these results, strain M1-21T represents a novel species of the genus Uliginosibacterium, for which the name Uliginosibacterium sediminicola sp. nov. is proposed. The type strain is M1-21T (=KACC 19271T=JCM 32000T).

Roseomonas fluminis sp. nov. isolated from sediment of a shallow stream.

An aerobic, Gram-negative, motile by means of a single polar flagellum, and ovoid-shaped bacterium, designated D3T, was isolated from shallow stream sediments in Sinan-gun, South Korea. Growth occurred at 15-40 °C (optimum 35 °C), at pH 7.0-8.0 (optimum pH 7.0), and at an optimum NaCl concentration of 0.5 % (w/v). The major cellular fatty acids (>7 % of the total) were C16 : 0, C18 : 0 2-OH, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The predominant quinone was ubiquinone-10, and the G+C content of the genomic DNA of strain D3T was 73.1 mol%. The major polyamine was spermidine. The major polar lipids of the isolate were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain D3T clustered with Roseomonas aquatica TR53T within the genus Roseomonas. The 16S rRNA gene sequence of strain D3T showed the highest sequence similarity to R. aquatica TR53T (95.9 %), followed by Roseomonas rosea 173-96T (95.7 %) and Roseomonas aerilata 5420S-30T (95.0 %). Based on the phenotypic, phylogenetic and chemotaxonomic characterization, strain D3T represents a novel species of the genus Roseomonas, for which the name Roseomonas fluminis sp. nov. is proposed. The type strain is D3T (=KACC 19269T=JCM 31968T).

Chthonobacter albigriseus gen. nov., sp. nov., isolated from grass-field soil.

A novel aerobic, Gram-stain-negative and non-motile bacterial strain, designated ED7T, was isolated from grass-field soil in Cheonan, Korea. Strain ED7T utilized methanol and methylamine, but not formate, as carbon and energy sources. The strain was able to grow at 20-42 °C (optimum 30-35 °C), at pH 7.0-8.5 (optimum pH 7.5-8.0), and in the absence of NaCl. According to the similarities of the 16S rRNA gene sequences, strain ED7T was most closely related to the genera Labrenzia (≤93.3 % 16S rRNA gene sequence similarity), Pleomorphomonas (≤93.1 %) and Prosthecomicrobium (≤93.1 %). A phylogenetic analysis based on the 16S rRNA gene sequence of strain ED7T revealed that it was affiliated with the family Methylocystaceae, being most closely related to the genus Pleomorphomonas. In contrast to Pleomorphomonas koreensis and Pleomorphomonas oryzae, strain ED7T did not contain the nifH gene. The DNA G+C content of the genomic DNA of strain ED7T was 71.8 mol%. The predominant fatty acids of strain ED7T were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), summed feature 2 (C14 : 0 3-OH, and/or C16 : 1 iso I), 11-methyl C18 : 1ω7c and C16 : 0 3-OH. The major isoprenoid quinone was ubiquinone 10 (Q-10). The major polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine and an unknown aminophospholipid. Based on phenotypic, chemotaxonomic and genotypic characteristic data, strain ED7T could be differentiated from other genera, suggesting that strain ED7T represents a novel species of a new genus in the family Methylocystaceae, for which the name Chthonobacter albigriseus gen. nov., sp. nov. is proposed. The type strain of the type species is ED7T (=JCM 30603T=KCTC 42450T).

Flavobacterium eburneum sp. nov., isolated from reclaimed saline land soil.

A novel Gram-stain-negative, motile by gliding, and aerobic bacterial strain, designated SA31T, was isolated from reclaimed saline land soil near a lake in Taean-gun, South Korea. Cells of the isolate formed ivory-coloured colonies. Growth occurred at 10-35 °C (optimum 25-30 °C), pH 6.0-9.0 (optimum pH 7.0-7.5), and 0-2.0 % (w/v) NaCl (optimum 0 %). Based on similarities of 16S rRNA gene sequences, strain SA31T was mostly affiliated with the genus Flavobacterium, exhibiting the highest sequence similarities with Flavobacterium palustre S44T (96.0 %), Flavobacterium glycines Gm-149T (95.9 %), Flavobacterium defluvii EMB117T (95.7 %) and Flavobacterium daejeonense GH1-10T (95.6 %). Phylogenetic analysis based on 16S rRNA gene sequences also indicated that strain SA31T was clustered with Flavobacterium daejeonense GH1-10T and Flavobacterium glycines Gm-149T. The predominant fatty acids (>7 % of total) of strain SA31T were iso-C15 : 0, summed feature 3 (C16 : 1ω7с and/or C16 : 1ω6с), iso-C17 : 0 3-OH and iso-C15 : 0 3-OH. The major polar lipids of the isolate comprised phosphatidylethanolamine, one unknown aminolipid, one unknown glycolipid, one unknown aminophospholipid and three unknown lipids. The major respiratory quinone was MK-6. The genomic DNA G+C content of strain SA31T was 33.5 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic analyses, strain SA31T represents a novel species the genus Flavobacterium, for which the name Flavobacterium eburneum sp. nov. is proposed. The type strain is SA31T (=KACC 18743T=JCM 31221T).

Sphingomonas silvisoli sp. nov., isolated from forest soil.

A novel Gram-stain-negative, aerobic, non-motile and short-rod-shaped bacterium, designated RP18T, was isolated from forest soil in Gwang-ju, Republic of Korea. Growth occurred at 15-30 °C (optimum 30 °C), pH 6.0-7.0 (optimum pH 7.0), and was inhibited in the presence of normal saline. According to the 16S rRNA gene sequence, strain RP18T showed the highest sequence similarity to Sphingomonas kyeonggiensis THG-DT81T (96.0 %), followed by Sphingomonas pituitosa EDIVT (95.4 %) and Sphingomonas dokdonensis DS-4T (95.2 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain RP18T was clustered with Sphingomonas gimensis 9PNM-6T and Sphingomonas jejuensis MS-31T under the genus Sphingomonas. The G+C content of the genomic DNA of strain RP18T was 61.5 mol%. The major cellular fatty acids (>6 % of the total) were C16 : 0, C14 : 0 2-OH, C17 : 1ω6с, summed feature 3 (C16 : 1ω7с and/or C16 : 1ω6с) and summed feature 8 (C18 : 1ω7с and/or C18 : 1ω6с). Ubiquinone-10 (Q-10) and sym-homospermidine were detected as the predominant respiratory quinone and major compound in the polyamine pattern, respectively. The major polar lipids of the isolate consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phospholipid and sphingoglycolipid. Based on phylogenetic analysis and physiological and biochemical characterization, strain RP18T represents a novel species of the genus Sphingomonas, for which the name Sphingomonas silvisoli sp. nov. is proposed. The type strain is RP18T (=KACC 18914T=JCM 31801T).

Sediminibacterium aquarii sp. nov., isolated from sediment in a fishbowl.

A novel bacterial strain, designated AA5T, was isolated from sediment in a fishbowl. Cells were Gram-stain-negative, rod-shaped and strictly aerobic, showing gliding motility. Strain AA5T was able to grow at 15-37 °C, at pH 5.0-8.0 and in the absence of NaCl. 16S rRNA gene sequence analysis revealed that strain AA5T was most closely related to species in the genus Sediminibacterium, showing highest similarity to the type strain of S.ediminibacterium goheungense (96.6 %). Concordantly, a phylogenetic tree based on 16S rRNA gene sequences indicated that strain AA5T belongs to the genus Sediminibacterium. The DNA G+C content was 44.7 mol%. The major polar lipids were phosphatidylethanolamine, four unidentified aminolipids, two unknown aminophospholipids and four unidentified polar lipids. The only respiratory quinone of strain AA5T was menaquinone 7 (MK-7) and the major fatty acids (>5 % of the total) were iso-C15 : 0, iso-C15 : 1 G, iso-C16 : 0 3-OH, iso-C17 : 0 3-OH and iso-C15 : 0 3-OH. Based on data from this polyphasic study, strain AA5T represents a novel species, for which the name Sediminibacterium aquarii sp. nov. is proposed. The type strain is AA5T (=KACC 18509T=JCM 31013T).

Emticicia sediminis sp. nov. isolated from sediment of a shallow stream.

A novel bacterial strain, designated JBR12T, was isolated from sediment of a shallow stream in Cheonan, Korea. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain JBR12T belongs to the genus Emticicia, and indicated that its closest relatives are Emticicia oligotrophica DSM 17448T (97.8 % sequence similarity) and E. ginsengisoli Gsoil 085T (94.3%). A DNA-DNA hybridization experiment revealed < 70 % genomic relatedness between strain JBR12T and E. oligotrophica DSM 17448T. The major fatty acids (>5% of the total) were iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), iso-C15 : 0 3-OH, anteiso-C15 : 0 and iso-C15 : 0 3-OH. The DNA G+C content of strain JBR12T was 37.7 mol%. According to data from the present polyphasic taxonomic study, strain JBR12T represents a novel species of the genus Emticicia, for which the name Emticicia sediminis sp. nov. is proposed. The type strain is JBR12T ( = KACC 17466T = JCM 19321T).

Oryzobacter terrae gen. nov., sp. nov., isolated from paddy soil.

A bacterial strain, PSGM2-16(T), was isolated from a pot of paddy soil grown with rice in Suwon region, Republic of Korea, and was characterized as having aerobic, Gram-stain-positive, short-rod-shaped cells with one polar flagellum. The 16S rRNA gene sequence of strain PSGM2-16(T) revealed the highest sequence similarities with Knoellia locipacati DMZ1T (97.4%), Fodinibacter luteus YIM C003(T) (97.2%) and Lapillicoccus jejuensis R-Ac013(T) (97.0%), and the phylogenetic tree showed that strain PSGM2-16(T) formed a subgroup with Ornithinibacter aureus HB09001(T) and F. luteus YIM C003(T) within the family Intrasporangiaceae. The major fatty acids (>10% of the total fatty acids) of strain PSGM2-16(T) were iso-C16 : 0, C17 : 1ω8c and iso-C14 : 0. The predominant menaquinone was MK-8(H4). The polar lipids present were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, three aminophospholipids and two phospholipids. The peptidoglycan was type A4γ with meso-diaminopimelic acid as the diagnostic diamino acid. DNA-DNA hybridization values between strain PSGM2-16(T) and closely related taxa were much less than 70%. The genomic DNA G+C content of strain PSGM2-16(T) was 70.0 mol%. On the basis of the evidence presented, it is concluded that strain PSGM2-16(T) represents a novel species of a new genus in the family Intrasporangiaceae, for which the name Oryzobacter terrae gen. nov., sp. nov. is proposed. The type strain of the type species is PSGM2-16(T) ( = KACC 17299(T)= DSM 27137(T)= NBRC 109598(T)).

Marmoricola solisilvae sp. nov. and Marmoricola terrae sp. nov., isolated from soil and emended description of the genus Marmoricola.

Two strains of species of the genus Marmoricola, designated KIS18-7T and JOS5-1T, were isolated from soil samples in Korea. The 16S rRNA gene sequence of strain KIS18-7T showed highest similarities with Marmoricola scoriae Sco-D01T (97.8 %), Marmoricola aequoreus SST-45T (97.6 %) and Marmoricola aurantiacus BC 361T (97.3 %), and strain JOS5-1T had highest sequence similarities with M. aequoreus SST-45T (97.5 %) and Marmoricola bigeumensis MSL-05T (97.3 %). The sequence similarity between KIS18-7T and JOS5-1T was 98.1 %. Phylogenetic analysis showed that these strains grouped with species of the genus Marmoricola. The major fatty acids of strain KIS18-7T were iso-C16 : 0 and C17 : 1ω8c, and C17 : 1ω8c, C18 : 0 10-methyl (TBSA), C18 : 1ω9c, C17 : 0 10-methyl and C16 : 0 2-OH for strain JOS5-1T. Strain KIS18-7T contained the polar lipids, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylcholine, while strain JOS5-1T contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, one unknown aminolipid and two unknown phospholipids. The peptidoglycan of both strains contained ll-diaminopimelic acid as the diagnostic diamino acid and a single glycine residue as the interpeptide bridge (type A3γ). The major menaquinone of both strains was MK-8(H4). The G+C contents of the DNA of strains KIS18-7T and JOS5-1T were 68.0 mol% and 62.9 mol%, respectively. These data demonstrate that strains KIS18-7T and JOS5-1T are representatives of two novel species of the genus Marmoricola, for which the names Marmoricola solisilvae sp. nov. (type strain KIS18-7T = KACC 17307T = DSM 27140T = NBRC 109601T) and Marmoricola terrae sp. nov. (type strain JOS5-1T = KACC 17308T = DSM 27141T = NBRC 109602T) are proposed.

Improved PCR assay for the species-specific identification and quantitation of Legionella pneumophila in water.

Legionellosis outbreak is a major global health care problem. However, current Legionella risk assessments may be compromised by uncertainties in Legionella detection methods, infectious dose, and strain infectivity. These limitations may place public health at significant risk, leading to significant monetary losses in health care. However, there are still unmet needs for its rapid identification and monitoring of legionellae in water systems. Therefore, in the present study, a primer set was designed based on a LysR-type transcriptional regulator (LTTR) family protein gene of Legionella pneumophila subsp. pneumophila str. Philadelphia 1 because it was found that this gene is structurally diverse among species through BLAST searches. The specificity of the primer set was evaluated using genomic DNA from 6 strains of L. pneumophila, 5 type strains of other related Legionella species, and other 29 reference pathogenic bacteria. The primer set used in the PCR assay amplified a 264-bp product for only targeted six strains of L. pneumophila. The assay was also able to detect at least 1.39 × 10(3) copies/µl of cloned amplified target DNA using purified DNA or 7.4 × 10(0) colony-forming unit per reaction when using calibrated cell suspension. In addition, the sensitivity and specificity of this assay were confirmed by successful detection of Legionella pneumophila in environmental water samples.

Flavihumibacter cheonanensis sp. nov., isolated from sediment of a shallow stream.

A Gram-reaction-positive, rod-shaped, strictly aerobic and non-motile bacterial strain, designated WS16(T), was isolated from the sediment of a shallow stream located in Cheonan, Korea. The strain grew optimally at 28 °C, at pH 7.0 and in the absence of NaCl. Phylogenetic trees based on 16S rRNA gene sequences suggested that the isolate belonged to the genus Flavihumibacter of the phylum Bacteroidetes. Comparative 16S rRNA gene sequence analysis showed that strain WS16(T) was related most closely to Flavihumibacter petaseus T41(T) (96.8 % similarity). The isolate contained MK-7 as the predominant menaquinone and iso-C15 : 0, iso-C15 : 1 and iso-C17 : 0 3-OH as the major fatty acids. The genomic DNA G+C content of the isolate was 45.9 mol%. The results of a polyphasic taxonomic approach indicated that strain WS16(T) represents a novel species of the genus Flavihumibacter, for which the name Flavihumibacter cheonanensis sp. nov. is proposed. The type strain is WS16(T) ( = KACC 17467(T) = JCM 19322(T)).

Mucilaginibacter koreensis sp. nov., isolated from leaf mould.

A Gram-staining-negative, strictly aerobic, rod-shaped, pale-pink pigmented bacterial strain, designated TF8(T), was isolated from leaf mould in Cheonan, Republic of Korea. Its taxonomic position was determined through a polyphasic approach. Optimal growth occurred on R2A agar without NaCl supplementation, at 25-28 °C and at pH 6.0-7.0. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain TF8(T) belongs to the genus Mucilaginibacter in the family Sphingobacteriaceae. The sequence similarity between 16S rRNA genes of strain TF8(T) and the type strains of other species of the genus Mucilaginibacter ranged from 92.1 to 94.7%. The closest relatives of strain TF8(T) were Mucilaginibacter lutimaris BR-3(T) (94.7%), M. soli R9-65(T) (94.5%), M. litoreus BR-18(T) (94.5%), M. rigui WPCB133(T) (94.0%) and M. daejeonensis Jip 10(T) (93.8%). The major isoprenoid quinone was MK-7 and the major cellular fatty acids were iso-C15 : 0 (33.0%), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c; 24.8%) and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c; 13.0%). The major polar lipids of TF8(T) were phosphatidylethanolamine and three unidentified aminophospholipids. The G+C content of the genomic DNA was 46.2 mol%. On the basis of the data presented here, strain TF8(T) is considered to represent a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter koreensis sp. nov. is proposed. The type strain is TF8(T) ( = KACC 17468(T) = JCM 19323(T)).

Jeotgalibaca dankookensis gen. nov., sp. nov., a member of the family Carnobacteriaceae, isolated from seujeot (Korean traditional food).

A novel, Gram-stain-positive bacterium, designated strain EX-07T, was isolated from seujeot (Korean traditional food). The strain was aerobic, halotolerant and non-motile; it formed cocci that grouped into tetrads and sarcinae or formed irregular conglomerates. Growth occurred at pH 7-9, at 10-37 °C and with up to 9% NaCl. Isolate EX-07T was catalase- and oxidase-negative and used sugars and organic acids as carbon sources. The 16S rRNA gene sequence of the novel strain showed 94.2-94.5% similarity with the type strains of Trichococcus pasteurii, Trichococcus patagoniensis, Trichococcus collinsii, Trichococcus flocculiformis and Trichococcus palustris and only 92.2% with representatives of the genera Bavariicoccus, Carnobacterium and Granulicatella. Sequence similarities based on the groEL gene ranged from 81.3 to 82.8% between the novel isolate and the type strains of all species of the genus Trichococcus, and only 74.2 and 75.3% with type strains of members of the genera Bavariicoccus and Granulicatella, respectively. The G+C content of the genomic DNA was 39.6 mol%. The predominant fatty acids were C16:1ω9c, C18:1ω9c, C16:0 and C14:0. The polar lipid profile was very complex and included phosphatidylethanolamine and several unidentified aminolipids, glycolipids and phospholipids. Based on the genotypic and phenotypic results obtained in this study, it is proposed that isolate EX-07T represents a novel species of a new genus in the family Carnobacteriaceae for which the name Jeotgalibaca dankookensis gen. nov., sp. nov. is proposed. The type strain of Jeotgalibaca dankookensis is EX-07T (=KCCM 90229T=JCM 19215T).

Description of Galbitalea soli gen. nov., sp. nov., and Frondihabitans sucicola sp. nov.

Bacterial strains KIS82-1(T) and GRS42(T) were isolated from soil and from sap of Acer mono, respectively, in the Republic of Korea. Both strains were aerobic, Gram-stain-positive, mesophilic, rod-shaped and motile. Phylogenetically, both strains belonged to the family Microbacteriaceae of the phylum Actinobacteria. The 16S rRNA gene sequence of strain KIS82-1(T) showed the highest similarity to those of Frondihabitans peucedani RS-15(T) (97.6%), Frigoribacterium mesophilum MSL-08(T) (97.2%) and Labedella gwakjiensis KSW2-17(T) (97.0%), while strain GRS42(T) showed the highest 16S rRNA gene sequence similarity to Frondihabitans peucedani RS-15(T) (98.7%), Frondihabitans cladoniiphilus CafT13(T) (98.4%), Frondihabitans australicus E1HC-02(T) (98.2%) and Frigoribacterium faeni 801(T) (97.3%). The 16S rRNA gene sequence similarity between GRS42(T) and KIS82-1(T) was 97.0%. Phylogenetic trees indicated that strain GRS42(T) was firmly grouped into the genus Frondihabitans, while strain KIS82-1(T) did not show a clear affiliation to any genus within the family Microbacteriaceae. Strain KIS82-1(T) showed type B1ß peptidoglycan with 2,4-diamino-L-butyric acid as the diamino acid. It had MK-11, MK-10 and MK-12 as respiratory quinones, anteiso-C(15 : 0), iso-C(16: 0) and iso-C(14 : 0) as major cellular fatty acids and diphosphatidylglycerol, phosphatidylglycerol and an unknown glycolipid as predominant polar lipids. The peptidoglycan of strain GRS42(T) was of type B2ß with D-ornithine as the diamino acid. The strain contained MK-8, MK-9 and MK-7 as respiratory quinones, summed feature 8 (C(18 : 1)ω6c and/or C(18 : 1)ω7c) as major cellular fatty acid and diphosphatidylglycerol, phosphatidylglycerol and three unknown glycolipids as predominant polar lipids. Strain GRS42(T) revealed low DNA-DNA hybridization (<50% relatedness) with closely related strains. Based on the data obtained in the present polyphasic taxonomic study, we propose that strain KIS82-1(T) represents a novel genus and species and that strain GRS42(T) represents a novel species in the family Microbacteriaceae. The genus Galbitalea gen. nov. is proposed, with strain KIS82-1(T) ( = KACC 15520(T) = NBRC 108727(T)) as the type strain of the type species, Galbitalea soli sp. nov. Strain GRS42(T) ( = KACC 15521(T) = NBRC 108728(T)) is proposed as the type strain of Frondihabitans sucicola sp. nov.

Nocardioides daecheongensis sp. nov., isolated from soil.

Strain KIS2-16(T) was isolated from a soil sample collected from Daecheong Island of Incheon region, South Korea. KIS2-16(T) was Gram-staining-positive, aerobic, non-spore-forming, non-motile, catalase-positive, oxidase-negative and mesophilic. On the basis of 16S rRNA gene sequence analysis, strain KIS2-16(T) represented a member of the genus Nocardioides, being most closely related to the type strains of species of the genus Nocardioides, Nocardioides maradonensis RP-B30(T) (97.8 % sequence similarity) and Nocardioides ultimimeridianus RP-B26(T) (97.0 %). The fatty acid profile of KIS2-16(T) was dominated by C18 : 1ω9c, C17 : 1ω8c, C16 : 0, C18 : 0 10-methyl (TBSA), C16 : 0 2-OH and C17 : 0 2-OH. The major isoprenoid quinone was MK-8(H4), and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol. The peptidoglycan structure was A3γ-type with ll-diaminopimelic acid. The genomic DNA G+C content of KIS2-16(T) was 64.9 mol%. Strain KIS2-16(T) showed DNA-DNA hybridization values of less than 70 % with the closely related species of the genus Nocardioides. Based on phenotypic, genotypic and phylogenetic data, the isolate represents a novel species of the genus Nocardioides, for which the name Nocardioides daecheongensis sp. nov. (type strain KIS2-16(T) = DSM 27136(T) = KACC 17297(T) = NBRC 109597(T)) is proposed.

Oryzihumus terrae sp. nov., isolated from soil and emended description of the genus Oryzihumus.

A Gram-stain-positive, aerobic, non-flagellated bacterium, designated KIS22-12(T), was isolated from a soil sample of Baengnyeong Island in Onjin county, Republic of Korea. Cells were non-spore-forming cocci showing catalase-positive and oxidase-negative reactions. Growth of strain KIS22-12(T) was observed between 10 and 35 °C (optimum, 28-30 °C), between pH 5.0 and 9.0 (optimum, pH 7.0) and with 0-3% (w/v) NaCl. Strain KIS22-12(T) contained MK-8(H4) as the predominant menaquinone, and C17 : 1ω8c, iso-C15 : 0 and anteiso-C15 : 0 as the major fatty acids. Strain KIS22-12(T) contained diphosphatidylglycerol, phosphatidylinositol, one unknown aminophospholipid, one unknown aminolipid, two unknown phospholipids and one unknown lipid. The peptidoglycan type was A1γ. The G+C content of the genomic DNA was 75.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain KIS22-12(T) formed a phyletic lineage with Oryzihumus leptocrescens KV-628(T). 16S rRNA gene sequence similarity between the two strains was 96.5%. On the basis of phenotypic, chemotaxonomic and molecular properties, strain KIS22-12(T) represents a novel species within the genus Oryzihumus, for which the name Oryzihumus terrae sp. nov. is proposed. The type strain is KIS22-12(T) ( = KACC 16543(T) = DSM 27161(T) = NBRC 109596(T)). An emended description of the genus Oryzihumus is also provided.

Sphingomonas aerophila sp. nov. and Sphingomonas naasensis sp. nov., isolated from air and soil, respectively.

Two strains, designated 5413J-26(T) and KIS18-15(T), were isolated from the air and forest soil, respectively, in South Korea. Cells of the two strains were Gram-stain-negative, aerobic, polar-flagellated and rod-shaped. According to the phylogenetic tree, strains 5413J-26(T) and KIS18-15(T) fell into the cluster of Sphingomonas sensu stricto. Strain 5413J-26(T) showed the highest sequence similarities with Sphingomonas trueperi LMG 2142(T) (96.6%), Sphingomonas molluscorum KMM 3882(T) (96.5%), Sphingomonas azotifigens NBRC 15497(T) (96.3 %) and Sphingomonas pituitosa EDIV(T) (96.1 %), while strain KIS18-15(T) had the highest sequence similarity with Sphingomonas soli T5-04(T) (96.8%), Sphingomonas pituitosa EDIV(T) (96.6%), Sphingomonas leidyi ATCC 15260(T) (96.6 %), Sphingomonas asaccharolytica NBRC 15499(T) (96.6 %) and Sphingomonas koreensis JSS26(T) (96.6 %). The 16S rRNA gene sequence similarity between strains 5413J-26(T) and KIS18-15(T) was 95.4 %. Ubiquinone 10 was the predominant respiratory quinone and homospermidine was the major polyamine. The major polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and several unidentified phospholipids and lipids. The main cellular fatty acids (>10% of the total fatty acids) of strain 5413J-26(T) were summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c), summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH) and C14 : 0 2-OH, and those of strain KIS18-15(T) were summed feature 8 and C16 : 0. Based on the results of 16S rRNA gene sequence analysis, and physiological and biochemical characterization, two novel species with the suggested names Sphingomonas aerophila sp. nov. (type strain 5413J-26(T) = KACC 16533(T) = NBRC 108942(T)) and Sphingomonas naasensis sp. nov. (type strain KIS18-15(T) = KACC 16534(T) = NBRC 108943(T)) are proposed.