Duganella ginsengisoli sp. nov., isolated from ginseng soil.

A Gram-stain-negative, rod-shaped bacterium, designated DCY83T, was isolated from soil of a ginseng field in Gwangju Province, Republic of Korea. Cells were motile by means of flagella. Growth occurred at 4-40 °C (optimum 30 °C), at pH 6-8 (optimum pH 7.0) and with ≤ 0.4 % NaCl. Strain DCY83T was able to produce siderophore and was positive for phosphate solubilization. Indole-3-acetic acid production was 12.9 µg ml- 1 after 3 days in culture. 16S rRNA gene sequence analysis showed that strain DCY83T belonged to the genus Duganella and was related most closely to Duganella sacchari Sac-22T (97.4 % similarity), Duganella zoogloeoides IAM 12670T (97.1 %) and Duganella radicis Sac-41T (97.1 %). The major fatty acids were C16 : 0 and summed feature 3 (containing C16 : 1ω7c and/or C16 : 1ω6c). The major polar lipids were phosphatidylglycerol and phosphatidylethanolamine. The only quinone was ubiquinone 8. The genomic DNA G+C content was 55.3 mol%. DNA-DNA relatedness between strain DCY83T and D. sacchari KCTC 22381T, D. zoogloeoides JCM 20729T and D. radicis KCTC 22382T was 27.7, 22.4 and 35.5 %, respectively. On the basis of the phenotypic and genotypic analysis, DCY83T is classified as representing a novel species in the genus Duganella, for which the name Duganella ginsengisoli sp. nov. is proposed. The type strain is DCY83T ( = KCTC 42409T = JCM 30745T).

Ginsenoside Rg5:Rk1 attenuates TNF-α/IFN-γ-induced production of thymus- and activation-regulated chemokine (TARC/CCL17) and LPS-induced NO production via downregulation of NF-κB/p38 MAPK/STAT1 signaling in human keratinocytes and macrophages.

Atopic dermatitis (AD) is a chronic skin disease that affects millions of people worldwide. Keratinocytes and macrophages are two cells types that play a pivotal role in the development of AD. These cells produced different chemokines and cytokines, especially thymus and activation-regulated chemokine (TARC/CCL17) and macrophage-derived chemokine (MDC/CCL22), as well as nitric oxide (NO) through inducible nitric oxide synthase (iNOS) and COX2 in response to stimulation by TNF-α/IFN-γ and lipopolysaccharide (LPS) respectively. These mediators are thought to be crucial regulators of the pathogenesis of AD. Although several natural compounds to treat AD have been studied, the effect of Rg5:Rk1 from Panax ginseng (P. ginseng) on AD has not yet been investigated. In this study, we evaluated the inhibitory effect of Rg5:Rk1 on TNF-α/IFN-γ stimulated keratinocytes (HaCaT cells) and LPS-stimulated macrophages (RAW 264.7 cells). Enzyme-linked immunosorbent assay (ELISA) data showed that pretreatment of HaCaT cells with Rg5:Rk1 significantly reduced the TNF-α/IFN-γ-induced increase in TARC/CCL17 expression in a dose-dependent manner. In addition, Rg5:Rk1 decreased LPS-mediated nitric oxide (NO) and reactive oxygen species (ROS) production in RAW 264.7 cells. A considerable reduction in messenger RNA (mRNA) expression of the aforementioned AD mediators was also observed. Pretreatment with Rg5:Rk1 attenuated the TNF-α/IFN-γ-induced phosphorylation of p38 MAPK, STAT1, and NF-κB/IKKß in HaCaT cells. Together, these findings suggest that ginsenoside Rg5:Rk1 may have a potential anti-AD effect by suppressing NF-κB/p38 MAPK/STAT1 signaling.

Labrys soli sp. nov., isolated from the rhizosphere of ginseng.

In this study, we describe strain DCY64T that was isolated from the rhizosphere of three-year-old Korean ginseng root. Cells were Gram-reaction negative, oxidase- and catalase-positive, strictly aerobic, capsulated, non-motile, non-sporulating and spherical to short rod-shaped. Multiplicative budding cells were produced. Vesicles covered the surface of cells. Phylogenetic analysis placed strain DCY64T within the genus Labrys with the highest similarity to Labrys monachus VKM B-1479T (97.6 % 16S rRNA gene sequence similarity), followed by Labrys okinawensis MAFF 210191T (97.5 %), Labrys miyagiensis G24103T (97.4) and Labrys portucalensis F11T (97.0 %). The genomic DNA G+C content was 63 mol%. The presences of summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), C19 : 1 cyclo ω8c and C16 : 0 as major fatty acids; phosphatidylmonomethylethanolamine, phosphatidylglycerol, phosphatidylcholine and diphosphatidylglycerol as major polar lipids; ubiquinone Q-10 as the predominant quinone and sym-homospermidine as the dominant polyamine were found in strain DCY64T. These chemotaxonomic results were in accordance with those of members of the genus Labrys. However, the absence of C16 : 0 2-OH, C16 : 0 3-OH and C18 : 1 2-OH from the fatty acids profile and differences in minor polar lipids and phenotypic characteristics distinguished strain DCY64T from the closest type strains. The discrimination was also supported by unique enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR) fingerprints, as well as DNA-DNA hybridization values ( ≤ 48 %) between strain DCY64T and related type strains. Therefore, we propose that strain DCY64T represents a novel species of the genus Labrys. The name Labrys soli sp. nov. is proposed, with DCY64T ( = KCTC 32173T = JCM 19895T) as the type strain.