Sphingomonas cremea sp. nov., isolated from ginseng soil.

A novel Gram-stain-negative, aerobic, rod-shaped, non-motile, cream-coloured strain (G124T) was isolated from ginseng soil collected in Yeongju, Republic of Korea. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain G124T belongs to a distinct lineage within the genus Sphingomonas (family Sphingomonadaceae, order Sphingomonadales and class Alphaproteobacteria). Strain G124T was closely related to Sphingomonas rhizophila THG-T61T (98.5 % 16S rRNA gene sequence similarity), Sphingomonas mesophila SYSUP0001T (98.3 %), Sphingomonas edaphi DAC4T (97.6 %) and Sphingomonas jaspsi TDMA-16T (97.6 %). The strain contained ubiquinone 10 as the major respiratory quinone. The major polar lipid profile of strain G124T comprised phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and sphingoglycolipids. The predominant cellular fatty acids of strain G124T were summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c; 33.4 %), summed feature 3 (C16 : 1 ω6c/C16 : 1 ω7c; 27.2 %) and C16 : 0 (18.3 %). The genome size of strain G124T was 2 549 305 bp. The genomic DNA G+C content is 62.0 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain G124T and other Sphingomonas species were in the range of 71.2-75.9 % and 18.7-19.9 %, respectively. Based on the polyphasic analysis such as biochemical, phylogenetic and chemotaxonomic characteristics, strain G124T represents a novel species of the genus Sphingomonas, for which the name Sphingomonas cremea sp. nov. is proposed. The type strain is G124T (=KACC 21691T=LMG 31729T).

Nocardioides panacis sp. nov., isolated from soil of a ginseng field.

A bacterial strain designated as G188T was isolated from ginseng field soil in the Republic of Korea. Phylogenetic analysis of 16S rRNA gene sequences showed that strain G188T formed a distinct lineage within the genus Nocardioides, family Nocardioidaceae, order Propionibacteriales. Sequence similarity revealed that strain G188T was most closely related to Nocardioides iriomotensis IR27-S3T (97.7 % 16S rRNA similarity). The genome size of strain G188T was 4 901 775 bp, and the genomic DNA G+C content was 72.3 mol%. The average nucleotide identity and DNA-DNA hybridization values with other Nocardioides species were less than 75.6 and 20.1 %, respectively. The main fatty acids of strain G188T were C17 : 0, C17 : 1 ω8c and iso-C16 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylinositol, and the major respiratory quinone was menaquinone 8, supporting that strain G188T was affiliated with the genus Nocardioides. Based on biochemical, chemotaxonomic and phylogenetic analyses, the novel species Nocardioides panacis G188T (KACC 21695T=LMG 31733T) is proposed.

Chryseobacterium panacisoli sp. nov., isolated from ginseng-cultivation soil with ginsenoside-converting activity.

A Gram-stain-negative, non-motile, non-spore-forming, aerobic, rod-shaped and yellow-pigmented bacterium, designated strain Gsoil 183T, was isolated from ginseng-cultivation soil sampled in Pocheon Province, Republic of Korea. This bacterium was characterized to determine its taxonomic position by using a polyphasic approach. Strain Gsoil 183T grew at 10-37 °C and at pH 5.0-9.0 on tryptic soy agar. Strain Gsoil 183T had ß-glucosidase activity, which was responsible for its ability to convert ginsenoside Rb1 (one of the dominant active components of ginseng) to F2. Based on 16S rRNA gene sequencing, strain Gsoil 183T clustered with species of the genus Chryseobacterium and appeared to be closely related to Chryseobacterium sediminis LMG 28695T (99.1 % sequence similarity), Chryseobacterium lactis NCTC 11390T (98.6%), Chryseobacterium rhizoplanae LMG 28481T (98.6%), Chryseobacterium oncorhynchi CCUG 60105T (98.5%), Chryseobacterium viscerum CCUG 60103T (98.4%) and Chryseobacterium joostei DSM 16927T (98.3%). Menaquinone MK-6 was the predominant respiratory quinone and the major fatty acids were iso-C15 : 0, iso-C17 : 0-3OH and summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c). The polar lipids were phosphatidylethanolamine, six unidentified glycolipids, five unidentified aminolipids and three unidentified lipids. The G+C content of the genomic DNA was 36.6 mol%. Digital DNA-DNA hybridization between strain Gsoil 183T and the type strains of C. sediminis, C. lactis, C. rhizoplanae, C. oncorhynchi, C. viscerum and C. joostei resulted in values below 70 %. Strain Gsoil 183T could be differentiated genotypically and phenotypically from the recognized species of the genus Chryseobacterium. The isolate therefore represents a novel species, for which the name Chryseobacterium panacisoli sp. nov. is proposed, with the type strain Gsoil 183T (=KACC 15033T=LMG 23397T).

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).

Exploration and Characterization of Novel Glycoside Hydrolases from the Whole Genome of Lactobacillus ginsenosidimutans and Enriched Production of Minor Ginsenoside Rg3(S) by a Recombinant Enzymatic Process.

BACKGROUND: Several studies have reported that ginsenoside Rg3(S) is effective in treating metastatic diseases, obesity, and various cancers, however, its presence in white ginseng cannot be estimated, and only a limited amount is present in red ginseng. Therefore, the use of recombinant glycosidases from a Generally Recognized As Safe (GRAS) host strain is a promising approach to enhance production of Rg3(S), which may improve nutritional activity, human health, and quality of life. METHOD: Lactobacillus ginsenosidimutans EMML 3041T, which was isolated from Korean fermented pickle (kimchi), presents ginsenoside-converting abilities. The strain was used to enrich the production of Rg3(S) by fermenting protopanaxadiol (PPD)-mix-type major ginsenosides (Rb1, Rb2, Rc, and Rd) in four different types of food-grade media (1, MRS; 2, Basel Food-Grade medium; 3, Basel Food-Grade medium-I, and 4, Basel Food-Grade medium-II). Due to its tendency to produce Rg3(S), the presence of glycoside hydrolase in Lactobacillus ginsenosidimutans was proposed, the whole genome was sequenced, and the probable glycoside hydrolase gene for ginsenoside conversion was cloned. RESULTS: The L. ginsenosidimutans EMML 3041T strain was whole genome sequenced to identify the target genes. After genome sequencing, 12 sets of glycoside hydrolases were identified, of which seven sets (α,ß-glucosidase and α,ß-galactosidase) were cloned in Escherichia coli BL21 (DE3) using the pGEX4T-1 vector system. Among the sets of clones, only one clone (BglL.gin-952) showed ginsenoside-transforming abilities. The recombinant BglL.gin-952 comprised 952 amino acid residues and belonged to glycoside hydrolase family 3. The enzyme exhibited optimal activity at 55 °C and a pH of 7.5 and showed a promising conversion ability of major ginsenoside Rb1→Rd→Rg3(S). The recombinant enzyme (GST-BglL.gin-952) was used to mass produce Rg3(S) from major ginsenoside Rb1. Scale-up of production using 50 g of Rb1 resulted in 30 g of Rg3(S) with 74.3% chromatography purity. CONCLUSION: Our preliminary data demonstrated that this enzyme would be beneficial in the preparation of pharmacologically active minor ginsenoside Rg3(S) in the functional food and pharmaceutical industries.

Caballeronia ginsengisoli sp. nov., isolated from ginseng cultivating soil.

A Gram-stain-negative, strictly aerobic, non-motile, ivory colored and rod-shaped bacterium (designated Gsoil 652T) isolated from ginseng cultivating soil, was characterized using a polyphasic approach to clarify its taxonomic position. Strain Gsoil 652T was observed to grow optimally at 30 °C and at pH 7.0 on R2A agar medium. Phylogenetic analysis, based on 16S rRNA gene sequences similarities, indicated that Gsoil 652T belongs to the genus Caballeronia of the family Burkholderiaceae and was most closely related to Caballeronia choica LMG 22940T (98.9%), Caballeronia udeis LMG 27134T (98.9%), Caballeronia sordidicola LMG 22029T (98.2%) and Caballeronia humi LMG 22934T (98.1%). The DNA G+C content was 62.1 mol% and Q-8 was the major isoprenoid quinone. The main polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, unidentified aminophospholipid, and unidentified phospholipid. The predominant fatty acids were C16:0, C17:0 cyclo and C19:0 cyclo ω8c. The DNA-DNA relatedness value between strain Gsoil 652T and closely related type strains of Caballeronia species were less than 36.0%. Moreover, strain Gsoil 652T could be distinguished phenotypically from the recognized species of the genus Caballeronia. The novel isolate, therefore, represents a novel species, for which the name Caballeronia ginsengisoli sp. nov. is proposed, with the type strain Gsoil 652T (= KACC 19441T = LMG 30326T).

Anti-Inflammatory Effect of Ginsenoside Rh2-Mix on Lipopolysaccharide-Stimulated RAW 264.7 Murine Macrophage Cells.

Ginsenoside Rh2, a protopanaxadiol saponin from ginseng, has been reported to have strong anti-inflammatory activity. However, the concentration of ginsenoside Rh2 is very low (>0.001%) in the total ginseng extracted, which is not enough for production despite its high pharmacological effects. Thus, in this study, we evaluated the anti-inflammatory effect of ginsenoside Rh2-mix (GRh2-mix) on lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophage cells. From the high-performance liquid chromatography analysis, it was confirmed that the GRh2-mix was mainly composed of 20(S)-Rh2, 20(R)-Rh2, Rk2, and Rh3. The LPS-stimulated RAW 264.7 cells were treated with different concentrations of GRh2-mix (100, 200, 400, 500 µg/mL). The cell counting kit-8 assay showed that the GRh2-mix treatment increased cell proliferation in LPS-stimulated RAW 264.7 murine macrophage cells. The GRh2-mix inhibited nitric oxide production in a dose-dependent manner, suggesting an anti-inflammatory effect. Furthermore, reverse transcription polymerase chain reaction and Western blot results also indicated that the GRh2-mix suppressed inflammatory genes such as iNOS, TNF-α, COX-2, IL-1ß, IL-6, and NF-κB. In summary, these results suggest that the GRh2-mix exhibits anti-inflammatory activity via the downregulation of the NF-κB pathway and has high efficiency with a simple production procedure.

Brevibacterium anseongense sp. nov., isolated from soil of ginseng field.

Gram-positive, aerobic, non-motile, pale-yellow, and rodshaped bacterium, designated as Gsoil 188T, was isolated from the soil of a ginseng field in Pocheon, South Korea. A phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that the strain formed a distinct lineage within the genus Brevibacterium and was most closely related to B. epidermidis NBRC 14811T (98.4%), B. sediminis FXJ8.269T (98.2%), B. avium NCFB 3055T (98.1%), and B. oceani BBH7T (98.1%), while it shared less than 98.1% identity with the other species of this genus. The DNA G + C content was 68.1 mol%. The predominant quinone was MK-8(H2). The major fatty acids were anteiso-C15:0 and anteiso-C17:0. The cell wall peptidoglycan of strain Gsoil 188T contained meso-diaminopimelic acid. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, and an unidentified aminolipid. The physiological and biochemical characteristics, low DNA-DNA relatedness values, and taxonomic analysis allowed the differentiation of strain Gsoil 188T from the other recognized species of the genus Brevibacterium. Therefore, strain Gsoil 188T represents a novel species of the genus Brevibacterium, for which the name Brevibacterium anseongense sp. nov. is proposed, with the type strain Gsoil 188T (= KACC 19439T = LMG 30331T).

Mesorhizobium hankyongi sp. nov. Isolated from Soil of Ginseng Cultivating Field.

A Gram-negative, non-spore-forming and rod-shaped, bacterium (designated Gsoil 531T) was isolated from soil of a ginseng field. On the basis of 16S rRNA gene sequence, strain Gsoil 531T clustered with species of the genus Mesorhizobium and was closely related to M. camelthorni CCNWXJ 40-4T (98.9%) and M. alhagi CCNWXJ12-2T (98.7%). The DNA G + C content was 62.9 mol% and the predominant quinone was ubiquinone-10 (Q-10). The major cellular fatty acids were C16:0, C19:0 cyclo ω8c and summed feature 8 (C18:1 ω7c/C18:1 ω6c). The DNA-DNA hybridization values were less than 35.0% between novel isolate and its closest reference strains M. camelthorni HAMBI 3020T, M. alhagi HAMBI 3019T and M tamadayense LMG 26736T. Physiological, biochemical and low values of DNA-DNA hybridization results enabled strain Gsoil 531T to be differentiated genotypically and phenotypically from all known species of the genus Mesorhizobium. Therefore, strain Gsoil 531T signifies a novel species of the genus Mesorhizobium, for which the name Mesorhizobium hankyongi sp. nov. is proposed. The type strain Gsoil 531T (= KACC 19443T = LMG 30463T).

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

A Gram-positive, rod-shaped, non-spore-forming, and aerobic bacterium (Gsoil 556T) was isolated from soil of a ginseng field and subjected to its taxonomic position. Based on 16S rRNA gene sequence similarity, strain Gsoil 556T was shown to belong to the genus Actinomadura of the family Thermomonosporaceae and was closely related to A. montaniterrae CYP1-1BT (99.3%), A. nitritigenes DSM 44137T (98.7%), and A. rudentiformis HMC1T (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 HMC1T and A. nitritigenes DSM 44137T. 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 C14:0, C16:0, C18:1 ω9c and summed feature 3 (C16:1 ω6c/C16:1 ω7c). All these data supported the affiliation of strain Gsoil 556T to the genus Actinomadura. The DNA-DNA hybridization between strain Gsoil 556T and its phylogenetically closest relatives were less than 40%. Furthermore, the results of physiological and biochemical tests enabled strain Gsoil 556T to be differentiated genotypically and phenotypically from currently known Actinomadura species. Therefore, strain Gsoil 556T represents a novel species of the genus Actinomadura, for which the name Actinomadura hankyongense sp. nov. is proposed. The type strain Gsoil 556T (=KACC 19438T=LMG 30327T).

Terrabacter ginsengisoli sp. nov., isolated from ginseng cultivating soil.

A Gram-positive, strictly aerobic, nonmotile, yellowish, coccus-rod-shaped bacterium (designated Gsoil 653T) isolated from ginseng cultivating soil was characterized using a polyphasic approach to clarify its taxonomic position. The strain Gsoil 653T exhibited optimal growth at pH 7.0 on R2A agar medium at 30°C. Phylogenetic analysis based on 16S rRNA gene sequence similarities, indicated that Gsoil 653T belongs to the genus Terrabacter of the family Humibacillus, and was closely related to Terrabacter tumescens DSM 20308T (98.9%), Terrabacter carboxydivorans PY2T (98.9%), Terrabacter terrigena ON10T (98.8%), Terrabacter terrae PPLBT (98.6%), and Terrabacter lapilli LR-26T (98.6%). The DNA G + C content was 70.5 mol%. The major quinone was MK-8(H4). The primary polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidyl-ethanolamine. The predominant fatty acids were iso-C15:0, iso-C16:0, iso-C14:0, and anteiso-C15:0, as in the case of genus Terrabacter, thereby supporting the categorization of strain Gsoil 653T. However, the DNA-DNA relatedness between Gsoil 653T and closely related strains of Terrabacter species was low at less than 31%. Moreover, strain Gsoil 653T could be both genotypically and phenotypically distinguished from the recognized species of the genus Terrabacter. This isolate, therefore, represents a novel species, for which the name Terrabacter ginsengisoli sp. nov. is proposed with the type strain Gsoil 653T (= KACC 19444T = LMG 30325T).

Polaromonas ginsengisoli sp. nov., isolated from ginseng field soil.

A Gram-reaction-negative, strictly aerobic, milky-white and rod-shaped bacterium (designated Gsoil 115T) isolated from ginseng field soil was characterized by a polyphasic approach to clarify its taxonomic position. Strain Gsoil 115T grew optimally at 30 °C and at pH 7.0 on Reasoner's 2A agar medium. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain Gsoil 115T belongs to the genus Polaromonas and was most closely related to Polaromonaseurypsychrophila B717-2T (98.6 %), Polaromonasvacuolata 34-PT (98.3 %), Polaromonasjejuensis NBRC 106434T (98.1 %), Polaromonas aquatic CCUG 39402T (97.7 %) and Polaromonascryoconiti Cr4-35T (97.5 %). The DNA G+C content was 60.9 mol%. The DNA-DNA hybridization relatedness between strain Gsoil 115T and P. eurypsychrophila B717-2T, P. vacuolata 34-PT, P. jejuensis NBRC 106434T, P. aquatic CCUG 39402T and P. cryoconiti Cr4-35T were 31.2, 21.6, 16.9, 8.7 and 10.1 %, respectively. The major polar lipids were phosphatidylglycerol (PG), diphosphatidylglycerol (DPG) and phosphatidylethanolamine (PE). The sole respiratory quinone was Q-8. The major fatty acids were C16 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), which supported the affiliation of strain Gsoil 115T to the genus Polaromonas. Moreover, the physiological, biochemical and low level of DNA-DNA relatedness value allowed the phenotypic and genotypic differentiation of strain Gsoil 115T from the recognized species of the genus Polaromonas. Therefore, strain Gsoil 115T represents a novel species of the genus Polaromonas, for which the name Polaromonas ginsengisoli sp. nov. is proposed, with the type strain Gsoil 115T (LMG 23393T=KCTC 12577T).

Aeromicrobium panacisoli sp. nov. Isolated from Soil of Ginseng Cultivating Field.

A Gram-positive, rod-shaped, non-spore-forming, and aerobic bacterium (Gsoil 137T) was isolated from soil of a ginseng field of Pocheon province in South Korea and subjected to a polyphasic approach in order to determine its taxonomic position. On the basis of 16S rRNA gene sequence similarity, strain Gsoil 137T was shown to belong to the family Nocardioidaceae and was closely related to Aeromicrobium ginsengisoli Gsoil 098T (96.7%), Aeromicrobium panaciterrae (96.7%), and Aeromicrobium halocynthiae JCM 15749T (96.6%). Being phylogenetic, it was most closely related to Aeromicrobium halocynthiae JCM 15749T. The G+C content of the genomic DNA was 70.3 mol%. The diagnostic diamino acid of the cell wall peptidoglycan was LL-diaminopimelic acid. The predominant menaquinone was menaquinone MK-8 (H4) and MK-7 (H4) was a minor compound. The major cellular fatty acids were C14:0, C16:0, C18:1 ω9c and summed feature 4 (C16:1 ω7c/C15:0 iso 2-OH). All these data supported the affiliation of strain Gsoil 137T to the genus Aeromicrobium. The results of physiological and biochemical tests enabled strain Gsoil 137T to be differentiated genotypically and phenotypically from currently known Aeromicrobium species. Therefore, strain Gsoil 137T represents a novel species of the genus Aeromicrobium, for which the name Aeromicrobium panacisoli sp. nov. is proposed. The type strain is Gsoil 137T (= KCTC 19130T = DSM 17940T = CCUG 52475T).

Baekduia soli gen. nov., sp. nov., a novel bacterium isolated from the soil of Baekdu Mountain and proposal of a novel family name, Baekduiaceae fam. nov.

A taxonomic study was conducted on BR7-21T, a bacterial strain isolated from the soil of a ginseng field in Baekdu Mountain. Comparative studies of the 16S rRNA gene sequence showed that the isolate was most closely related to Conexibacter woesei DSM 14684T, Solirubrobacter pauli ATCC BAA-492T, Patulibacter minatonensis JCM 12834T, with 93.8%, 92.4%, and 91.5% sequence similarity, respectively; each genus represented a family in the order Solirubrobacterales. Strain BR7-21T was Gram-reaction positive, non-spore forming, aerobic, non-motile, and short rod-shaped. It grew well on half-strength R2A medium. The G + C content of the genomic DNA was 73.9%. It contained meso-diaminopimelic acid in the cell wall and the major menaquinones were MK-7(H4) and MK-8(H4). The major fatty acids were summarized as (C16:1ω7c/iso-C15:0 2-OH), iso-C16:0, and C17:0 cyclo. On the basis of polyphasic evidence, it was proposed that strain BR7-21T should be placed in a new genus and species, for which the name Baekduia soli gen. nov., sp. nov. was proposed with the type strain BR7-21T (= KCTC 22257T = LMG 24797T). The family Baekduiaceae fam. nov. is proposed to encompass the genus Baekduia gen. nov.

Biotic elicitation of ginsenoside metabolism of mutant adventitious root culture in Panax ginseng.

Biotic elicitation is an important biotechnological strategy for triggering the accumulation of secondary metabolites in adventitious root cultures. These biotic elicitors can be obtained from safe, economically important strains of bacteria found in the rhizosphere and fermented foods. Here, we assayed the effects of filtered cultures of five nitrogen-fixing bacteria and four types of fermentation bacteria on mutant adventitious Panax ginseng root cultures induced in a previous study by colchicine treatment. The biomass, pH, and electrical conductivity (EC) of the culture medium were altered at 5 days after treatment with bacteria. The saponin content was highest in root cultures treated with Mesorhizobium amorphae (GS3037), with a concentration of 105.58 mg g-1 dry weight saponin present in these cultures versus 74.48 mg g-1 dry weight in untreated root cultures. The accumulation of the ginsenosides Rb2 and Rb3 dramatically increased (19.4- and 4.4-fold, and 18.8- and 4.8-fold) 5 days after treatment with M. amorphae (GS3037) and Mesorhizobium amorphae (GS336), respectively. Compound K production increased 1.7-fold after treatment with M. amorphae (GS3037) compared with untreated root cultures. These results suggest that treating mutant adventitious root cultures with biotic elicitors represents an effective strategy for increasing ginsenoside production in Panax ginseng.

Mucilaginibacter panaciglaebae sp. nov., isolated from soil of a ginseng field.

A Gram-reaction-negative, strictly aerobic, non-motile and rod-shaped bacterium, designated strain BXN5-31T, was isolated from soil of a ginseng field, and its taxonomic position was investigated using a polyphasic approach. Strain BXN5-31T grew at 18-37 °C and at pH 6.0-8.0 on R2A medium. Based on 16S rRNA gene sequence similarity, strain BXN5-31T was shown to belong to the genus Mucilaginibacter and was closely related to Mucilaginibactersoyangensis HME6664T, Mucilaginibacterximonensis XM-003T and Mucilaginibacterpuniceus WS71T. The DNA G+C content was 43.6 %. The predominant respiratory quinone was menaquinone 7 (MK-7) and the major fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH and summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c). The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol and phosphatidylethanolamine. The DNA-DNA hybridization values between strain BXN5-31T and three reference strains (M. soyangensis HME6664T, M. ximonensis XM-003T and M. puniceus WS71T) were 9.4±1.9, 8.2±1.3 and 5.7±0.7 %, respectively. The DNA G+C content and chemotaxonomic data supported the affiliation of strain BXN5-31T to the genus Mucilaginibacter. Moreover, the physiological and biochemical results and low level of DNA-DNA relatedness allowed the phenotypic and genotypic differentiation of strain BXN5-31T from recognized species of the genus Mucilaginibacter. The isolate therefore represents a novel species, for which the name Mucilaginibacter panaciglaebae sp. nov. is proposed. The type strain is BXN5-31T (=KACC 14957T=JCM 17085T).

Phenylobacterium hankyongense sp. nov., isolated from ginseng field soil.

A Gram-stain-negative, aerobic, non-motile, non-spore-forming and rod-shaped bacterial strain, designated HKS-05T, was isolated from ginseng field soil. This bacterium was characterized to determine its taxonomic position by using the polyphasic approach. HKS-05T grew at 10-37 °C and at pH 6.0-8.0 on R2A agar. On the basis of 16S rRNA gene sequence similarity, HKS-05T was shown to represent a member of the family Caulobacteraceaeand to be related to Phenylobacterium lituiforme FaiI3T (98.1 % sequence similarity), 'Phenylobacterium zucineum' HLK1 (97.9 %), Phenylobacterium muchangponense A8T (97.7 %), Phenylobacteriumcomposti 4T-6T (97.2 %) and Phenylobacterium immobile ET (97.1 %). The major respiratory quinone was Q-10 and the major fatty acids were summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c), C16 : 0, and summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c). The polar lipids were phosphatidylglycerol, unidentified glycolipids and unidentified polar lipids. The G+C content of the genomic DNA was 70.4 mol%. DNA-DNA relatedness values between HKS-05T and its closest phylogenetically neighbours were low. HKS-05T could be differentiated genotypically and phenotypically from the species of the genus Phenylobacterium with validly published names. The isolate therefore represents a novel species, for which the name Phenylobacteriumhankyongense sp. nov. is proposed, with the type strain HKS-05T (=KACC 18628T=LMG 30081T).

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 3017T was isolated from soil of ginseng field and investigated by phenotypic and phylogenetic analyses. Strain Gsoil 3017T 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 3017T possessed ß-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 FT22T (95.6%) and Mucilaginibacter gotjawali SA3-7T (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-C15:0, iso-C17:0 3-OH, and summed feature 3 (comprising C16:1 ω6c and/or C16:1 ω7c). The major polar lipid was phosphatidylethanolamine. Strain Gsoil 3017T 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 3017T (=KACC 14954T = JCM 17081T).

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 BR5-28T was isolated from the soil of a ginseng field at Baekdu Mountain Korea, and its taxonomic position was investigated using a polyphasic approach. Strain BR5-28T 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 ß-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 FT22T (95.8%) and Mucilaginibacter gotjawali SA3-7T (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 C16:1 ω6c and/or C16:1 ω7c), iso-C15:0 and anteiso-C15:0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Strain BR5-28T 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 BR5-28T (=KCTC 22274T =DSM 21151T).

Production of the Rare Ginsenoside Rh2-MIX (20(S)-Rh2, 20(R)-Rh2, Rk2, and Rh3) by Enzymatic Conversion Combined with Acid Treatment and Evaluation of Its Anti-Cancer Activity.

The ginsenoside Rh2 has strong anti-cancer, anti-inflammatory, and anti-diabetic effects. However, the application of ginsenoside Rh2 is restricted because of the small amounts found in Korean white and red ginsengs. To enhance the production of ginsenoside Rh2-MIX (comprising 20(S)-Rh2, 20(R)-Rh2, Rk2, and Rh3 as a 10-g unit) with high specificity, yield, and purity, a new combination of enzymatic conversion using the commercial enzyme Viscozyme L followed by acid treatment was developed. Viscozyme L treatment at pH 5.0 and 50°C was used initially to transform the major ginsenosides Rb1, Rb2, Rc, and Rd into ginsenoside F2, followed by acid-heat treatment using citric acid 2% (w/v) at pH 2.0 and 121°C for 15 min. Scale-up production in a 10-L jar fermenter, using 60 g of the protopanaxadiol-type ginsenoside mixture from ginseng roots, produced 24 g of ginsenoside Rh2-MIX. Using 2 g of Rh2-MIX, 131 mg of 20(S)-Rh2, 58 mg of 20(R)-Rh2, 47 mg of Rk2, and 26 mg of Rh3 were obtained at over 98% chromatographic purity. Then, the anti-cancer effect of the four purified ginsenosides was investigated on B16F10, MDA-MB-231, and HuH-7 cell lines. As a result, these four rare ginsenosides markedly inhibited the growth of the cancer cell lines. These results suggested that rare ginsenoside Rh2-MIX could be exploited to prepare an anti-cancer supplement in the functional food and pharmaceutical industries.