Andean soil-derived lignocellulolytic bacterial consortium as a source of novel taxa and putative plastic-active enzymes

An easy and straightforward way to engineer microbial environmental communities is by setting up liquid enrichment cultures containing a specific substrate as the sole source of carbon. Here, we analyzed twenty single-contig high-quality metagenome-assembled genomes (MAGs) retrieved from a microbial consortium (T6) that was selected by the dilution-to-stimulation approach using Andean soil as inoculum and lignocellulose as a selection pressure. Based on genomic metrics (e.g., average nucleotide and amino acid identities) and phylogenomic analyses, 15 out of 20 MAGs were found to represent novel bacterial species, with one of those (MAG_26) belonging to a novel genus closely related to Caenibius spp. (Sphingomonadaceae). Following the rules and requirements of the SeqCode, we propose the name Andeanibacterium colombiense gen. nov., sp. nov. for this taxon. A subsequent functional annotation of all MAGs revealed that MAG_7 (Pseudobacter hemicellulosilyticus sp. nov.) contains 20, 19 and 16 predicted genes from carbohydrate-active enzymes families GH43, GH2 and GH92, respectively. Its lignocellulolytic gene profile resembles that of MAG_2 (the most abundant member) and MAG_3858, both of which belong to the Sphingobacteriaceae family. Using a database that contains experimentally verified plastic-active enzymes (PAZymes), twenty-seven putative bacterial polyethylene terephthalate (PET)-active enzymes (i.e., alpha/beta-fold hydrolases) were detected in all MAGs. A maximum of five putative PETases were found in MAG_3858, and two PETases were found to be encoded by A. colombiense. In conclusion, we demonstrate that lignocellulose-enriched liquid cultures coupled with genome-resolved metagenomics are suitable approaches to unveil the hidden bacterial diversity and its polymer-degrading potential in Andean soil ecosystems.

Longitalea arenae gen. nov., sp. nov. and Longitalea luteola sp. nov., two new members of the family Chitinophagaceae isolated from desert soil

Two strains designated as SYSU D01084^T and SYSU D00799^T, were isolated from a sandy soil sample collected from Gurbantunggut Desert in Xinjiang, north-west China. Cells of both strains were Gram-stain-negative, strictly aerobic, long-rod-shaped, oxidase- and catalase-negative, motile or non-motile. Colonies were circular, translucent, convex, smooth and light-yellow in color on R2A agar. The two isolates were found to grow at 4-50 ºC, at pH 6.0-8.0 and with 0-1.0% (w/v) NaCl. Analysis of their 16S rRNA gene sequences indicated that they belonged to the family Chitinophagaceae, and closely related to the genera Paraflavitalea, Niastella, Pseudoflavitalea and Flavitalea. The two novel strains shared 98.1% 16S rRNA sequence similarity and represent different species on the basis of low average nucleotide identity (ANI, 83.8%) and digital DNA-DNA hybridization (dDDH, 51.4%) values. The genomic DNA G + C contents of strains SYSU D01084^T and SYSU D00799^T were 46.0 and 45.6%, respectively. Phylogenetic trees showed that the two isolates were clustered in an individual lineage and not grouped consistently into any specific genus. The polar lipids contained of phosphatidylethanolamine, four unidentified aminolipids, two unidentified aminoglycolipids, and three or four unidentified lipids. The predominant respiratory quinone was MK-7 and the major fatty acids (> 10%) were identified as iso-C_15:0, iso-C_17:0 3-OH, and iso-C_15:1 G. Based on the combined phenotypic, genomic and phylogenetic analyses, the two strains represent two novel species of a new genus in the family Chitinophagaceae, for which the name Longitalea gen. nov. is proposed, comprising the type species Longitalea arenae sp. nov. (type strain SYSU D01084^T = CGMCC 1.18641^T = MCCC 1K05006^T = KCTC 82283^T) and Longitalea luteola sp. nov. (type strain SYSU D00799^T = MCCC 1K04987^T = KCTC 82282^T = NBRC 114888^T).

Phnomibacter ginsenosidimutans gen. nov., sp. nov., a novel glycoside hydrolase positive bacterial strain with ginsenoside hydrolysing activity

The conversion of major ginsenosides into minor ginsenosides attracts a lot of interest because of their biological and pharmaceutical activities. Therefore, for the conversion of ginsenosides, finding a novel competent glycoside hydrolase-producing bacterial strain is useful for future research studies and the mass production of minor ginsenosides. Wastewater samples were collected and screened for novel glycoside hydrolase bacterial strains using Reasoner's 2A+aesculin agar medium. As a result, a novel glycoside hydrolase positive bacterial strain (SB-02^T) was identified and subjected to a polyphasic taxonomic analysis. Based on genome analysis, strain SB-02^T was found to be affiliated with the family Chitinophagaceae and have less than 92.8 % sequence similarity to other members of the same family. Functional analysis indicated that SB-02^T was able to hydrolyse the ginsenosides Rb1, Rc and Rd to F2 and C-K. Due to the conversion of ginsenosides, the strain's genome was sequenced and the genes were annotated by the NCBI. The average amino acid identity and average nucleotide identity values between SB-02^T and the available reference genomes were 65.7 and 65.9 %, respectively. The novel isolate contained MK-7 as the predominant menaquinone, the major polyamine putrescine, and iso-C_15 : 0, iso-C_15 : 1 G and iso-C_17 : 0 3-OH as major fatty acids. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Thus, based on the data presented here, strain SB-02^T represents a novel species within a new genus in the family Chitinophagaceae, for which the name Phnomibacter ginsenosidimutans gen. nov., sp. nov. is proposed. The type strain of Phnomibacter ginsenosidimutans is SB-02^T (=KACC 21266^T=LMG 31707^T). The genome annotation of SB-02^T shows many glycoside hydrolase genes, which may be responsible for the efficient production of many kinds of minor ginsenosides and will be very helpful for future research (target gene cloning) and mass production of either F2 or C-K.

Paraflavitalea devenefica sp. nov., isolated from urban soil

A Gram-stain-negative, rod-shaped, mesophilic, milky white-pigmented, aerobic, non-spore-forming and non-flagellated bacterium, designated strain X16^T, was isolated from urban soil of Zibo, Shandong, China. According to 16S rRNA gene sequence analysis, the isolate showed highest similarities with Paraflavitalea soli 5GH32-13^T (97.6 %), Pseudoflavitalea soli KIS20-3^T (96.2 %), Pseudobacter ginsenosidimutans Gsoil 221^T (96.0 %) and Pseudoflavitalea rhizosphaerae T16R-265^T (95.8 %). The neighbour-joining tree based on 16S rRNA gene sequences showed that strain X16^T formed a subcluster with Paraflavitalea soli 5GH32-13^T, and the subcluster was closely related to Pseudoflavitalea soli KIS20-3^T, Pseudobacter ginsenosidimutans Gsoil 221^T and Pseudoflavitalea rhizosphaerae T16R-265^T. Strain X16^T also formed a subcluster with Paraflavitalea soli 5GH32-13^T in phylogenetic tree based on genomic sequences. The polar lipids are phosphatidylethanolamine, two unknown aminolipids, two unknown aminophospholipids, two unknown lipids and two unknown phospholipids. The major quinone of strain X16^T is menaquinone-7 and the main fatty acids (>10 % of total fatty acids) of strain X16^T are iso-C_15 : 0, iso-C_17 : 0 3-OH and iso-C_15 : 1 G. The genome length of strain X16^T is 8.7 Mb with a DNA G+C content of 47.4 %. ANI values among strain X16^T and strain Paraflavitalea soli 5GH32-13^T, Pseudobacter ginsenosidimutans Gsoil 221^T, and Pseudoflavitalea rhizosphaerae T16R-265^T are 78.1, 70.7, 70.6 %, respectively. On the basis of the results of the polyphasic characterization presented in this study, it is concluded that strain X16^T represents a novel species. Besides, strain X16^T can detoxify high toxicity selenite [Se(IV)] to low toxicity elemental selenium [Se(0)], for which the name Paraflavitale devenefica sp. nov. is proposed. The type strain is X16^T (=KACC 21698^T=GDMCC1.1757^T).

Isolation, characterisation and genome analysis of a novel ginsenosides hydrolysing bacterium Ginsengibacter hankyongi gen. nov., sp. nov. isolated from soil

A novel yellow-pigmented bacterial strain (designated BR5-29^T), was isolated and its taxonomy was studied. Phylogenetic study based on the 16S rRNA and draft genome sequence placed the strain BR5-29^T in a distinct lineage within the family Chitinophagaceae, sharing ≤ 93.4% sequence similarity with members of the closely related genera Ferruginibacter, Flavisolibacter, Flavitalea and Niastella. The novel isolate showed the highest sequence similarity to the genus Ferruginibacter. The draft genome of strain BR5-29^T had a total length of 5,505,520 base pairs. A total of 4585 genes were identified, in which 4537 were CDS and 48 RNA genes were assigned a putative function. The genome annotation of BR5-29^T showed 225 carbohydrate genes which may be responsible for the conversion of major ginsenosides to minor ginsenosides. Strain BR5-29^T contained MK-7 as a predominant quinone, and iso-C_15:0, iso-C_15:0 G, iso-C_17:0 3-OH, and C_16:1 ω7c and/or C_16:1 ω6c (summed feature 3) as major fatty acids. The polar lipids found in the strain BR5-29^T were phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), five unidentified polar lipids (L1-L5), two unidentified aminolipid and one unidentified aminophospholipid. Our pilot data demonstrate that the novel isolate shares the similar major polar lipid PE, major quinone MK-7 and major fatty acids with the described members of the family Chitinophagaceae. However, the low 16S rRNA gene sequence (< 93.4%), the little high amount of C_12:0, iso-C_17:0 2-OH and iso-C_15:1 2-OH fatty acids, low DNA G + C content, and the presence of DPG, PG and two unidentified polar lipids (L1 and L3 differentiate the BR5-29^T from its closest phylogenetic neighbors. Thus, the isolate represents a novel genus and species in the family Chitinophagaceae for which the name Ginsengibacter hankyongi gen. nov., sp. nov. is proposed. The type strain is BR5-29^T (= KACC 19446^T = LMG 30462^T). Thus, we predict that this novel strain may prove useful for the future research analysis (target gene cloning) and mass production of Rg3.

Agriterribacter humi gen. nov., sp. nov., a novel bacterium of the family Chitinophagaceae isolated from soil of a farming field

A Gram-stain-negative bacterium, designated strain YJ03^T, was isolated from a spinach farming field soil at Shinan in Korea. Strain YJ03^T was found to be an aerobic, non-motile and non-spore-forming bacterium which can grow at 10-33 °C (optimum, 25-28 °C), at pH 6.6-9.5 (optimum, pH 7.0-7.5) and at salinities of 0-1.0 % (w/v) NaCl (optimum, 0 % NaCl). Sequence similarities of the 16S rRNA gene of strain YJ03^T with the closely related relatives were in the range 93.9-92.2 %, and the results of phylogenomic analysis indicated that strain YJ03^T was clearly separated from species of the genera in the family Chitinophagaceae, showing average nucleotide identity values of 68.8-64.3 %. The predominant isoprenoid quinone was identified as MK-7 and the major fatty acids were iso-C_15 : 0, iso-C_17 : 0 3-OH and an unidentified fatty acid with an equivalent chain-length of 13.565. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, four unidentified aminolipids and six unidentified lipids. The G+C content of the genome was determined to be 41.8 mol%. On the basis of phenotypic and chemotaxonomic properties and phylogenetic and phylogenomic analyses using 16S rRNA gene sequences and whole-genome sequences in this study, strain YJ03^T is considered to represent a novel species of a new genus in the family Chitinophagaceae, for which the name Agriterribacter humi gen. nov., sp. nov., is proposed. The type strain of Agriterribacter humi is YJ03^T (=KACC 19548^T=NBRC 113195^T).

Parapseudoflavitalea muciniphila gen. nov., sp. nov., a member of the family Chitinophagaceae isolated from a human peritoneal tumour and reclassification of Pseudobacter ginsenosidimutans as Pseudoflavitalea ginsenosidimutans comb. nov

A Gram-stain-negative, microaerophilic, non-motile, rod-shaped bacterium strain designated PMP191F^T, was isolated from a human peritoneal tumour. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the organism formed a lineage within the family Chitinophagaceae that was distinct from members of the genus Pseudoflavitalea (95.1-95.2 % sequence similarity) and Pseudobacter ginsenosidimutans (94.4 % sequence similarity). The average nucleotide identity values between strain PMP191F^T and Pseudoflavitalea rhizosphaerae T16R-265^T and Pseudobacter ginsenosidimutans Gsoil 221^T was 68.9 and 62.3% respectively. The only respiratory quinone of strain PMP191F^T was MK-7 and the major fatty acids were iso-C_15 : 0, iso-C_15 : 1 G and summed feature 3 (C_16:1 ω7c and/or C_16:1 ω6c). The polar lipids consisted of phosphatidylethanolamine and some unidentified amino and glycolipids. The G+C content of strain PMP191F^T calculated from the genome sequence was 43.4 mol%. Based on phylogenetic, phenotypic and chemotaxonomic evidence, strain PMP191F^T represents a novel species and genus for which the name Parapseudoflavitalea muciniphila gen. nov., sp. nov. is proposed. The type strain is PMP191F^T (=DSM 104999^T=ATCC BAA-2857^T = CCUG 72691^T). The phylogenetic analyses also revealed that Pseudobacter ginsenosidimutans shared over 98 % sequence similarly to members of the genus Pseudoflavitalea. However, the average nucleotide identity value between Pseudoflavitalea rhizosphaerae T16R-265^T, the type species of the genus and Pseudobacter ginsenosidimutans Gsoil 221^T was 86.8 %. Therefore, we also propose that Pseudobacter ginsenosidimutans be reclassified as Pseudoflavitalea ginsenosidimutans comb. nov.

Devosia ginsengisoli sp. nov., isolated from ginseng cultivation soil

A Gram-stain-negative, strictly aerobic, motile, ivory-coloured and rod-shaped bacterium (designated Gsoil 520T) isolated from ginseng cultivation soil was characterized by using a polyphasic approach to clarify its taxonomic position. Strain Gsoil 520T was observed to grow optimally at 30 °C and pH 7.0 on Reasoner's 2A agar medium. The results of phylogenetic analysis, based on 16S rRNA gene sequence similarities, indicated that Gsoil 520T belongs to the genus Devosia of the family Hyphomicrobiaceae and was most closely related to Devosia epidermidihirudinis E84T (98.0 %), Devosia yakushimensis Yak96BT (97.7 %), Devosia neptuniae J1T (97.7 %) and Devosia chinhatensis IPL18T (96.8 %). The complete genome of strain Gsoil 520T is a presumptive circular chromosome of 4 480 314 base pairs having G+C content of 63.7 mol%. A total of 4 354 genes, 4 303 CDS and 43 rRNA genes were assigned a putative function. The major isoprenoid quinone was Q-10. The main polar lipids were phosphatidylglycerol, diphosphatidylglycerol and two unidentified aminolipids (AL1 and AL3). The predominant fatty acids of strain Gsoil 520T were C18 : 1ω7c 11-methyl, C16 : 0 and C18 : 1ω7c/C18 : 1ω6c (summed feature 8) supporting the affiliation of strain Gsoil 520T to the genus Devosia . The low values of DNA–DNA hybridization distinguished strain Gsoil 520T from the recognized species of the genus Devosia . Thus, the novel isolate represents a novel species of the genus Devosia , for which the name Devosia ginsengisoli sp. nov. is proposed, with the type strain Gsoil 520T (=KACC 19440T=LMG 30329T).

Paracnuella aquatica gen. nov., sp. nov., a member of the family Chitinophagaceae isolated from a hot spring

A Gram-stain-negative, rod-shaped bacterium (designated strain N24^T) with gliding motility was isolated from thermal spring water sampled at Xi'an, PR China. Cells were 0.4-0.8 µm wide and 1.8-7.8 µm long. Optimal growth occurred at 33 °C and pH 7.0 on Reasoner's 2A (R2A) agar. Strain N24^T could produce exopolysaccharide on R2A agar at 33 °C. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain N24^T formed a distinct phyletic lineage within the family Chitinophagaceae and was most closely related to members of the genera Flavisolibacter, Cnuella, Niveitalea, Flavitalea, Flaviaesturariibacter and Niastella with 91.7-93.9 % 16S rRNA gene sequence similarities. The major fatty acids of strain N24^T were iso-C15 : 0 (31.8 %), iso-C17 : 0 3-OH (16.1 %) and iso-C15 : 1 G (12.9 %). The polar lipid profile consisted of phosphatidylethanolamine, two aminolipids and six unknown lipids; the quinone system consisted of menaquinone-7 (MK-7). The genomic G+C content was 49.3 mol%. On the basis of the evidence presented in this study, strain N24^T represents a novel species of a new genus in the family Chitinophagaceae, for which the name Paracnuella aquatica gen. nov., sp. nov. is proposed. The type species is N24^T (=KCTC 62083^T=MCCC 1H00301^T).

Gynurincola endophyticus gen. nov., sp. nov., a novel bacterium of the family Chitinophagaceae

A Gram-stain-negative, rod-shaped (0.2-0.4 µm×1.2-1.7 µm), endophytic bacterium, designated HBUM179779^T, was isolated from the stem of a medicinal plant,Gynura bicolor, collected from Pixian county in Sichuan province, China. The strain did not produce endospores and its cells could secrete mucus. The predominant menaquinone was MK-7. The polar lipids were phosphatidylethanolamine, phosphatidylinositolmannosides, two unknown aminolipids, two unknown glycolipids and an unknown phospholipid. Branched fatty acids (iso-) and hydroxy fatty acids were the main fatty acids, which mainly included iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain HBUM179779^T fell within the family Chitinophagaceae, and its closest neighbour was Pseudoflavitalea rhizosphaerae T16R-265^T (94.46 %). However, strain HBUM179779^T did not make a coherent clade with members of the recognized organisms. The average nucleotide identity value between strain HBUM179779^T and Pseudoflavitalea rhizosphaerae T16R-265^T was 67.1 %. On the basis of the phylogenetic and phenotypic characteristics of this bacterium, a novel genus and species, Gynurincola endophyticus gen. nov., sp. nov., is proposed. The type strain is HBUM179779^T (=CGMCC 1.15525^T=NBRC 112424^T).

Actinomadura hankyongense sp. nov. Isolated From Soil of Ginseng Cultivating Field

A Gram-positive, rod-shaped, non-spore-forming, and aerobic bacterium (Gsoil 556^T) was isolated from soil of a ginseng field and subjected to its taxonomic position. Based on 16S rRNA gene sequence similarity, strain Gsoil 556^T was shown to belong to the genus Actinomadura of the family Thermomonosporaceae and was closely related to A. montaniterrae CYP1-1B^T (99.3%), A. nitritigenes DSM 44137^T (98.7%), and A. rudentiformis HMC1^T (98.5%), while it showed less than 98.4% sequence similarity to the other species of this genus. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that it is most closely related to A. rudentiformis HMC1^T and A. nitritigenes DSM 44137^T. The DNA G+C content was 73.1 mol%. The peptidoglycan was meso-diaminopimelic acid and the whole-cell sugar contained fucose, galactose, glucose, mannose, and ribose. The predominant menaquinone (KK) was MK-9(H₈) [55%] and MK-9(H₆) [45%]. The major cellular fatty acids were C_14:0, C_16:0, C_18:1 ω9c and summed feature 3 (C_16:1 ω6c/C_16:1 ω7c). All these data supported the affiliation of strain Gsoil 556^T to the genus Actinomadura. The DNA-DNA hybridization between strain Gsoil 556^T and its phylogenetically closest relatives were less than 40%. Furthermore, the results of physiological and biochemical tests enabled strain Gsoil 556^T to be differentiated genotypically and phenotypically from currently known Actinomadura species. Therefore, strain Gsoil 556^T represents a novel species of the genus Actinomadura, for which the name Actinomadura hankyongense sp. nov. is proposed. The type strain Gsoil 556^T (=KACC 19438^T=LMG 30327^T).

Mucilaginibacter ginsenosidivorans sp. nov., Isolated from Soil of Ginseng Field

A Gram-reaction-negative, aerobic, nonmotile, nonspore-forming, and rod-shaped bacterial strain designated Gsoil 3017^T was isolated from soil of ginseng field and investigated by phenotypic and phylogenetic analyses. Strain Gsoil 3017^T grew at 10-37 °C (optimal growth at 30 °C) and at pH 5.5-8.0 (optimal growth at pH 7) on R2A and nutrient agar without additional NaCl as a supplement. Strain Gsoil 3017^T possessed β-glucosidase activity, which was responsible for its ability to transform ginsenosides Rb₁, Rc, and Rd (the three dominant active components of ginseng) to F₂ and C-K, respectively. Based on 16S rRNA gene phylogeny, the novel strain represents a new branch within the genus Mucilaginibacter family Sphingobacteriaceae, and clusters with Mucilaginibacter frigoritolerans FT22^T (95.6%) and Mucilaginibacter gotjawali SA3-7^T (95.6%). The G+C content of the genomic DNA was 48.7%. The predominant respiratory quinone was MK-7, and the major fatty acids were iso-C_15:0, iso-C_17:0 3-OH, and summed feature 3 (comprising C_16:1 ω6c and/or C_16:1 ω7c). The major polar lipid was phosphatidylethanolamine. Strain Gsoil 3017^T could be differentiated genotypically and phenotypically from other type strains of the genus Mucilaginibacter. The isolate therefore represents a novel species, for which the name Mucilaginibacter ginsenosidivorans sp. nov. is proposed, with the type strain Gsoil 3017^T (=KACC 14954^T = JCM 17081^T).

Mucilaginibacter ginsenosidivorans sp. nov., Isolated from Soil of Ginseng Field

A Gram-reaction-negative, aerobic, nonmotile, nonspore-forming, and rod-shaped bacterial strain designated Gsoil 3017^T was isolated from soil of ginseng field and investigated by phenotypic and phylogenetic analyses. Strain Gsoil 3017^T grew at 10-37 °C (optimal growth at 30 °C) and at pH 5.5-8.0 (optimal growth at pH 7) on R2A and nutrient agar without additional NaCl as a supplement. Strain Gsoil 3017^T possessed β-glucosidase activity, which was responsible for its ability to transform ginsenosides Rb₁, Rc, and Rd (the three dominant active components of ginseng) to F₂ and C-K, respectively. Based on 16S rRNA gene phylogeny, the novel strain represents a new branch within the genus Mucilaginibacter family Sphingobacteriaceae, and clusters with Mucilaginibacter frigoritolerans FT22^T (95.6%) and Mucilaginibacter gotjawali SA3-7^T (95.6%). The G+C content of the genomic DNA was 48.7%. The predominant respiratory quinone was MK-7, and the major fatty acids were iso-C_15:0, iso-C_17:0 3-OH, and summed feature 3 (comprising C_16:1 ω6c and/or C_16:1 ω7c). The major polar lipid was phosphatidylethanolamine. Strain Gsoil 3017^T could be differentiated genotypically and phenotypically from other type strains of the genus Mucilaginibacter. The isolate therefore represents a novel species, for which the name Mucilaginibacter ginsenosidivorans sp. nov. is proposed, with the type strain Gsoil 3017^T (=KACC 14954^T = JCM 17081^T).

Daejeonia ginsenosidivorans gen. nov., sp. nov., a ginsenoside-transforming bacterium isolated from lake water

A Gram-stain-negative, oxidase- and catalase-positive, strictly aerobic, non-gliding bacterial strain, designated as NPT, was isolated from lake water and subjected to a taxonomic study using a polyphasic approach. Colonies of strain NP5T were light-yellow-coloured, circular with regular margins, and opaque. Cells were rods, 0.2-0.5 µm wide and 1.2-3.0 µm long. Strain NP5T possessed β-glycosidase activity, which was responsible for its ability to convert ginsenosides Rb1, Rc and Rd (three main active components of ginseng) to ginsenoside F2. Phylogenetic study based on the 16S rRNA gene sequence put strain NP5T in a distinct lineage in the family Flavobacteriaceae, sharing less than 96.0 % sequence similarity with members of the closely related genera Chryseobacterium, Bergeyella, Epilithonimonas and 'Candidatus Amoebinatus'. The novel isolate showed the highest sequence similarity with the genus Chryseobacterium. Strain NP5T contained MK-6 as predominant quinone, and iso-C15 : 0, iso-C17 : 0 3-OH, iso-C16 : 0 3-OH, C18 : 0 3-OH, anteiso-C15 : 0 and C16 : 1ω7c and/or C16 : 1ω6c (summed feature 3) as major fatty acids. The DNA G+C content was 44.8 mol%. The main polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The physiological, biochemical and taxonomical characteristics allowed the phenotypic differentiation of strain NP5T from its closest phylogenetic neighbours. On the basis of the evidence of this polyphasic study, isolate NP5T represents a novel genus and species in the family Flavobacteriaceae for which the name Daejeonia ginsenosidivorans gen. nov., sp. nov. is proposed. The type strain is NP5T (=KACC 18626T=LMG 29198T).

Mucilaginibacter hankyongensis sp. nov., isolated from soil of ginseng field Baekdu Mountain

A Gram-negative, non-motile, aerobic, and rod-shaped bacterial strain designated as BR5-28^T was isolated from the soil of a ginseng field at Baekdu Mountain Korea, and its taxonomic position was investigated using a polyphasic approach. Strain BR5-28^T grew at 10-42°C (optimum temperature, 30°C) and pH 5.5-8.5 (optimum pH, 7.0) on R2A agar medium without additional NaCl supplementation. Strain BR5- 28T exhibited β-glucosidase activity, which was responsible for its ability to transform the ginsenosides Rb1 and Rd (the two dominant active components of ginseng) to compound-K. Based on 16S rRNA gene phylogeny, the novel strain showed a new branch within the genus Mucilaginibacter of the family Sphingobacteriaceae, and formed clusters with Mucilaginibacter frigoritolerans FT22^T (95.8%) and Mucilaginibacter gotjawali SA3-7^T (95.7%). The G+C content of the genomic DNA was 45.1%. The predominant respiratory quinone was MK-7 and the major fatty acids were summed feature 3 (comprising C_16:1 ω6c and/or C_16:1 ω7c), iso-C_15:0 and anteiso-C_15:0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Strain BR5-28^T was differentiated genotypically and phenotypically from the recognized species of the genus Mucilaginibacter. The isolate therefore represents a novel species, for which the name Mucilaginibacter hankyongensis sp. nov. is proposed, with the type strain BR5-28^T (=KCTC 22274^T =DSM 21151^T).

Arachidicoccus ginsenosidivorans sp. nov., with ginsenoside-converting activity isolated from ginseng cultivating soil

A Gram-reaction-negative, catalase- and oxidase-positive, aerobic, non-motile, light yellow and rod-shaped bacterium (designated Gsoil 809T) isolated from soil of ginseng field, was characterized by a polyphasic approach to clarify its taxonomic position. Strain Gsoil 809T was observed to grow optimally at 30 °C and at pH 7.0 on nutrient agar medium. Strain Gsoil 809T possessed β-glucosidase activity, which was responsible for its ability to transform protopanaxatriol-type ginsenoside Rg1 to ginsenoside Rh1. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain Gsoil 809T belongs to the genus Arachidicoccus of the family Chitinophagaceae and was most closely related to Arachidicoccusrhizosphaerae Vu-144T (98.1 % 16S rRNA gene sequence similarity). The DNA G+C content was 39.4 mol%. The DNA-DNA hybridization value between strain Gsoil 809T and A.rhizosphaerae Vu-144T was 41.27±1.03 %. The major polar lipids were phosphatidylethanolamine and an unknown polar lipid. The predominant quinone was MK-7. The major fatty acids were iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 0 3-OH and summed feature 3, which supported the affiliation of Gsoil 809T to the genus Arachidicoccus. Strain Gsoil 809T contained homospermidineas the major polyamine. Moreover, the physiological and biochemical test results and low DNA-DNA relatedness value allowed the phenotypic and genotypic differentiation of strain Gsoil 809T from recognized species of the genus Arachidicoccus. Therefore, strain Gsoil 809T represents a novel species of the genus Arachidicoccus, for which the name Arachidicoccus ginsenosidivorans sp. nov. is proposed. The type strain is Gsoil 809T (=KCTC 22820T=JCM 30984T).

Niveitalea solisilvae gen. nov., sp. nov., isolated from forest soil and emended description of the genus Flavihumibacter Zhang et al. 2010

A Gram-stain-negative and strictly aerobic bacterial strain, designated 6-4T, was isolated from forest soil in Jeju island, South Korea. Cells showing oxidase-positive and catalase-negative reactions were thin and long non-motile rods. Growth of strain 6-4T was observed at 20-35 °C (optimum, 30 °C) and pH 6.0-9.0 (optimum, pH 7.0). Strain 6-4T contained iso-C15 : 0, anteiso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH as the major fatty acids and menaquinone-7 (MK-7) as the sole isoprenoid quinone. Phosphatidylethanolamine was the major polar lipid and five unidentified aminolipids, one unidentified aminophospholipid and one unidentified lipid were also detected as minor polar lipids. The G+C content of the genomic DNA was 45.8 mol%. Strain 6-4T was most closely related to Flavihumibacter solisilvae 3-3T with a low 16S rRNA gene sequence similarity (94.2 %) and phylogenetic analysis indicated that the strain formed a distinct phylogenetic lineage from members of the genus Flavihumibacter and other closely related genera. On the basis of phylogenetic inference and phenotypic, chemotaxonomic and molecular properties, strain 6-4T represents a novel species of a new genus of the family Chitinophagaceae, for which the name Niveitalea solisilvae gen. nov., sp. nov. is proposed. The type strain of Niveitalea solisilvae is 6-4T (=KACC 18808T=JCM 31525T). An emended description of the genus Flavihumibacter is also proposed.

Compostibacter hankyongensis gen. nov., &nbsp;sp. nov., isolated from compost

A novel bacterial strain, designated strain BS27T, was isolated from mushroom compost and subjected to a taxonomic study using a polyphasic approach. Colonies of BS27T were milky-white, circular with regular fringes and opaque. Cells were short rods, 0.3-0.5 µm wide and 1.2-2.0 µm long. Phylogenetic study based on the 16S rRNA gene sequence placed BS27T in a distinct lineage in the family Chitinophagaceae, sharing 90.1-90.9 % sequence similarity with members of the closely related genera Chitinophaga, Flavitalea, Flavihumibacter, Lacibacter and Flavisolibacter. The novel isolate showed the highest sequence similarities with the members of the genus Chitinophaga. BS27T contained MK-7 as predominant quinone, and iso-C15 : 0, iso-C17 : 0 3-OH, C16 : 1ω7c and/or C16 : 1ω6c (summed feature 3) and iso-C17 : 1I and/or anteiso-C17 : 1B (summed feature 4) as major fatty acids. The DNA G+C content was 53.0 mol%. The major polar lipids of BS27T were phosphatidylethanolamine (PE) and five unidentified polar lipids (L1, L2, L5, L6 and L7). The results of physiological and biochemical tests allowed phenotypic differentiation of BS27T from its closest phylogenetic neighbours. On the basis of the evidence of this polyphasic study, isolate BS27T represents a novel genus and species in the family Chitinophagaceae for which the name Compostibacter hankyongensisgen. nov., sp. nov. is proposed. The type strain is BS27T (=KACC 18745T=JCM 17664T).