Nocardioides luti sp. nov., belonging to the family Nocardioidaceae isolated from kaolinite, exhibiting the biosynthesis potential of alkylresorcinol.

A novel Gram-staining-positive, short rod-shaped, non-motile, and non-pigmented actinobacterial strain (KIGAM211T) was isolated from kaolinite, a soft white clay mineral, collected from Sancheong in the Republic of Korea. On the basis of 16S rRNA gene sequence analysis, strain KIGAM211T was determined to belong to the genus Nocardioides and was most closely related to N. ungokensis UKS-03T (97.5% similarity). Cells could grow between 4 and 35 °C (optimum 30 °C), 0-3% (w/v) NaCl concentration (optimum 0%) and pH 5.5-8.5 (optimum 7.0) on R2A agar. Morphological appearance of colonies was cream-white, arranged singly or in groups. Biochemical characterization of strain KAGAM211T indicated that it could hydrolyze casein, gelatin, Tweens 40 and tyrosine. Furthermore, the strain was positive for both oxidase and catalase activity. Strain KIGAM211T was characterized chemotaxonomically by MK-8 (H4) as the predominant menaquinone and phosphatidylglycerol (PG) and phosphatidylinositol (PI) as the major polar lipids. Major fatty acids were iso-C16:0 and C18:1 ω9c. The Ortholog average nucleotide identity (OrthoANI) and in silico DNA-DNA hybridization (isDDH) values between strain KIGAM211T and its most closely related strains of the Nocardioides genus were < 82% and < 24%, respectively, suggesting that strain KIGAM211T represent a novel species. The whole genome size of KIGAM211T was 4.52 Mb, comprising a total of 4,294 genes with DNA G + C content of 72.3 mol%. The genome of strain KIGAM211T also comprises the biosynthetic gene cluster for alkylresorcinol as secondary metabolite. The results of physiological, taxonomical, phylogenetic, and whole genome analyses allowed for differentiation of strain KIGAM211T from the recognized Nocardioides species. Therefore, strain KIGAM211T is considered to represent a novel species, for which the name Nocardioides luti sp. nov. (type strain KIGAM211T = KCTC 49364T = JCM 33859T) is proposed.

Hymenobacter lutimineralis sp. nov., belonging to the family Hymenobacteraceae, isolated from zeolite.

A red-pigmented bacterial strain, designated KIGAM108T, within the family Hymenobacteraceae was isolated from zeolite in the Gampo-41 mine of the Gyeongju, Republic of Korea. This strain was a Gram-negative, strictly aerobic, non-spore forming, rod-shaped bacterium. Phylogenetic analysis of the 16S rRNA gene sequence of strain KIGAM108T found that it was related to the genus Hymenobacter, with similarities of 96.6, 96.4, 95.5, and 95.0% to H. fastidiosus VUG-A124T, H. algoricola VUG-A23aT, H. crusticola MIMBbqt21T, and H. daecheongensis DSM 21074T, respectively. Strain KIGAM108T grew in the presence of 0-0.5% (w/v) NaCl at 4-37 °C and pH 6.0-10.0. This isolate contained MK-7 as a respiratory quinone. The polar lipids of strain KIGAM108T were identified as phosphatidylethanolamine, two unidentified aminophospholipids, one unidentified phospholipid and five unidentified lipids. The major fatty acids profile showed summed feature 3 (C16:1ω6c and/or C16:1ω7c) (22.3%), anteiso-C15:0 (17.1%), C16:1ω5c (13.3%), and iso-C15:0 (11.0%). The genomic DNA G + C content was 60.0 mol%. Based on the polyphasic taxonomic data, strain KIGAM108T is considered to represent a novel species of the genus Hymenobacter, for which the name Hymenobacter lutimineralis sp. nov. is proposed. The type strain is KIGAM108T (=KCTC 72263T =JCM 33444T).

Effects of bentonite Bgp35b-p on the gut microbiota of mice fed a high-fat diet.

BACKGROUND: Bentonite is a natural clay mineral with health-promoting effects due to its high adsorption abilities with high cation-exchange capacity. Previously, we found an anti-obesity effect for Bgp35b-p bentonite produced in South Korea, where its high adsorbent ability of dietary lipids possibly partially removed the lipidic environment in the gut (unpublished). It is hypothesized that Bgp35b-p affects the intestinal microbial community, and thus the microbial changes were investigated via next-generation sequencing targeting the bacterial 16S rRNA gene and bioinformatics using QIIME (Quantitative Insights Into Microbial Ecology) were performed on feces of C57BL/6 male mice fed a high-fat diet (HFD) with the Bgp35b-p. RESULTS: The HFD caused microbial dysbiosis, characterized by a decrease in the relative abundance of Bacteroidetes and an increase in abundance of Firmicutes and Proteobacteria. It was found that HFD + Bgp35b-p led to significant changes in the microbial compositions of family-level bacteria known as short-chain fatty-acid-producing bacteria. The relative abundance of Ruminococcaceae was significantly increased, and the abundances of Clostridiaceae and Lachnospiraceae were decreased by HFD + Bgp35b-p, shifting close to that in mice fed a normal diet. CONCLUSION: Bgp35b-p induced compositional changes in intestinal microbiota, which can be considered as a prebiotic effect, thus suggesting that bentonite may be a potential prebiotic functional supplement. © 2018 Society of Chemical Industry.

Protein tyrosine phosphatase 1B (PTP1B) inhibitors from Morinda citrifolia (Noni) and their insulin mimetic activity.

As part of our ongoing search for new antidiabetic agents from medicinal plants, we found that a methanol extract of Morinda citrifolia showed potential stimulatory effects on glucose uptake in 3T3-L1 adipocyte cells. Bioassay-guided fractionation of this active extract yielded two new lignans (1 and 2) and three new neolignans (9, 10, and 14), as well as 10 known compounds (3-8, 11-13, and 15). The absolute configurations of compounds 9, 10, and 14 were determined by ECD spectra analysis. Compounds 3, 6, 7, and 15 showed inhibitory effects on PTP1B enzyme with IC50 values of 21.86 ± 0.48, 15.01 ± 0.20, 16.82 ± 0.42, and 4.12 ± 0.09 µM, respectively. Furthermore, compounds 3, 6, 7, and 15 showed strong stimulatory effects on 2-NBDG uptake in 3T3-L1 adipocyte cells. This study indicated the potential of compounds 3, 6, 7, and 15 as lead molecules for antidiabetic agents.

Isolation of the putative biosynthetic gene cluster of 1-deoxynojirimycin by Bacillus amyloliquefaciens 140N, its production and application to the fermentation of soybean paste.

The 1-deoxynojirimycin (DNJ) biosynthetic gene cluster of Bacillus amyloliquefaciens 140N isolated from traditional Korean fermented food was isolated by PCR screening. It showed 78.9% inhibitory activity against α-glucosidase and produced 0.8 g/L of DNJ in an optimized medium containing 2% soluble starch, 1% tryptone, 0.05% KH(2)PO(4), and 0.05% (NH(2))(4)SO(4). Soybean paste fermented with B. amyloliquefaciens 140N produced DNJ with 84.4% inhibitory activity.

Expression and characterization of a glutamate decarboxylase from Lactobacillus brevis 877G producing γ-aminobutyric acid.

The glutamate decarboxylase of γ-aminobutyric acid-producing Lactobacillus brevis 877G (LbGAD) was expressed in Escherichia coli. The optimal pH and temperature for the purified LbGAD activity were respectively determined to be pH 5.2 and 45 °C. CaCl2 was shown to be a potent activator of this LbGAD activity. The kinetic parameters for LbGAD were a Km value of 3.6 mmol/L and a Vmax value of 0.06 mmol/L/min for L-monosodium glutamate.

A Novel Carotenoid-Producing Bacterium, Paenibacillus aurantius sp. nov., Isolated from Korean Marine Environment.

The novel bacterial strain MBLB1776T was isolated from marine mud in Uljin, the Republic of Korea. Cells were Gram-positive, spore-forming, non-motile, and non-flagellated rods. Growth was observed at a temperature range of 10-45 °C, pH range of 6.0-8.0, and NaCl concentrations of 0-4% (w/v). Phylogenetic analysis of the 16S rRNA gene sequence revealed that MBLB1776T belonged to the genus Paenibacillus and was closely related to Paenibacillus cavernae C4-5T (94.83% similarity). Anteiso-C15:0, iso-C16:0, C16:0, and iso-C15:0 were the predominant fatty acids. Menaquinone 7 was identified as the major isoprenoid quinone. The major polar lipids included diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. Its whole genome was 6.3 Mb in size, with a G+C content of 55.8 mol%. Average nucleotide identity and in silico DNA-DNA hybridization values were below the species delineation threshold. Gene function analysis revealed the presence of a complete C30 carotenoid biosynthetic pathway. Intriguingly, MBLB1776T harbored carotenoid pigments, imparting an orange color to whole cells. Based on this comprehensive polyphasic taxonomy, the MBLB1776T strain represents a novel species within the genus Paenibacillus, for which the name Paenibacillus aurantius sp. nov is proposed. The type strain was MBLB1776T (=KCTC 43279T = JCM 34220T). This is the first report of a carotenoid-producing Paenibacillus sp.

Draft genome sequence of Staphylococcus vitulinus F1028, a strain isolated from a block of fermented soybean.

Staphylococcus vitulinus is a coagulase-negative staphylococcus in the family Staphylococcaceae. This report describes the draft genome sequence of S. vitulinus F1028, which was isolated from a traditional Korean soybean food (meju). This 2.56-Mbp genome sequence is the first S. vitulinus genome of a strain isolated from a fermented soybean product.

Genome sequence of Lysinibacillus boronitolerans F1182, isolated from a traditional Korean fermented soybean product.

Lysinibacillus is a Gram-positive, rod-shaped, and round-spore-forming bacterial genus of the family Bacillaceae. We analyzed the genome sequence of Lysinibacillus boronitolerans F1182, isolated from a traditional Korean fermented soybean product. The genome sequence contained 4.46 Mbp with a G+C content of 37.5%. This is the first report of an L. boronitolerans genome.

Genome sequence of Kocuria atrinae C3-8, isolated from Jeotgal, a traditional Korean fermented seafood.

Kocuria is a Gram-positive coccus, catalase-positive, coagulase-negative, strictly aerobic bacterial genus in the family Micrococcaceae. Kocuria atrinae C3-8 was isolated from a traditional Korean fermented seafood. This study describes the first genome sequence of K. atrinae strain C3-8, which has a 3.19-Mbp genome and a G+C content of 63.8%.

Genome sequence of Staphylococcus lentus F1142, a strain isolated from Korean soybean paste.

This report describes the draft genome sequence of Staphylococcus lentus F1142, which was isolated from a Korean fermented soybean paste (doenjang). The draft genome sequence contained 2.79 Mbp with a G+C content of 31.8%; this is the first S. lentus genome to be reported.

Antidiabetic Effect of Morinda citrifolia (Noni) Fermented by Cheonggukjang in KK-A(y) Diabetic Mice.

Antidiabetic effects of Morinda citrifolia (aka Noni) fermented by Cheonggukjang (fast-fermented soybean paste) were evaluated using a T2DM (type 2 diabetes mellitus) murine model. Six-week-old KK-Ay/TaJcl mice were randomly divided into four groups: (1) the diabetic control (DC) group, provided with a normal mouse diet; (2) the positive control (PC) group, provided with a functional health food diet; (3) the M. citrifolia (MC) group, provided with an MC-based diet; (4) the fermented M. citrifolia (FMC) group, provided with an FMC-based diet. Over a testing period of 90 days, food and water intake decreased significantly in the FMC and PC groups compared with the DC group. Blood glucose levels in the FMC group were 211.60-252.20 mg/dL after 90 days, while those in the control group were over 400 mg/dL after 20 days. In addition, FMC supplementation reduced glycosylated hemoglobin (HbA1c) levels, enhanced insulin sensitivity, and significantly decreased serum triglycerides and low-density lipoprotein (LDL) cholesterol. Furthermore, a fermented M. citrifolia 70% ethanolic extract (FMCE) activated peroxisome proliferator-activated receptor-(PPAR-) γ and stimulated glucose uptake via stimulation of AMP-activated protein kinase (AMPK) in cultured C2C12 cells. These results suggest that FMC can be employed as a functional health food for T2DM management.

Genomic and Physiological Characterization of Metabacillus flavus sp. nov., a Novel Carotenoid-Producing Bacilli Isolated from Korean Marine Mud.

The newly isolated strain KIGAM252T was found to be facultatively anaerobic, Gram-stain-positive, spore-forming, and rod-shaped. They grew at 10-45 °C, pH 6.0-10.0, and were able to tolerate up to 6% NaCl in the growth medium. Phylogenetic analysis indicated that the KIGAM252T strain was related to the genus Metabacillus. The cell membrane fatty acid composition of strain KIGAM252T included C15:0 anteiso and C15:0 iso (25.6%) as the major fatty acids, and menaquinone 7 was the predominant isoprenoid quinone. The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The size of the whole genome was 4.30 Mbp, and the G + C content of the DNA was 43.8%. Average nucleotide and amino acid identity and in silico DNA-DNA hybridization values were below the species delineation threshold. Pan-genomic analysis revealed that 15.8% of all genes present in strain KIGAM252T was unique to the strain. The analysis of the secondary biosynthetic pathway predicted the carotenoid synthetic gene cluster in the strain KIGAM252T. Based on these current polyphasic taxonomic data, strain KIGAM252T represents a novel species of the genus Metabacillus that produces carotenoids, for which we propose the name Metabacillus flavus sp. nov. The type of strain was KIGAM252T (=KCTC 43261T = JCM 34406T).

Chalcones as novel influenza A (H1N1) neuraminidase inhibitors from Glycyrrhiza inflata.

The emergence of highly pathogenic influenza A virus strains, such as the new H1N1 swine influenza (novel influenza), represents a serious threat to global human health. During our course of an anti-influenza screening program on natural products, one new licochalcone G (1) and seven known (2-8) chalcones were isolated as active principles from the acetone extract of Glycyrrhiza inflata. Compounds 3 and 6 without prenyl group showed strong inhibitory effects on various neuraminidases from influenza viral strains, H1N1, H9N2, novel H1N1 (WT), and oseltamivir-resistant novel H1N1 (H274Y) expressed in 293T cells. In addition, the efficacy of oseltamivir with the presence of compound 3 (5 µM) was increased against H274Y neuraminidase. This evidence of synergistic effect makes this inhibitor to have a potential possibility for control of pandemic infection by oseltamivir-resistant influenza virus.

Optimization of antibacterial activity of Perilla frutescens var. acuta leaf against Pseudomonas aeruginosa using the evolutionary operation-factorial design technique.

This study was undertaken to optimize the conditions for the extraction of antibacterial activity of Perilla frutescens var. acuta leaf against Pseudomonas aeruginosa KCTC 2004 using the evolutionary operation-factorial (EVOP) design technique. Increased antibacterial activity was achieved at higher extraction temperatures and with a longer extraction time. Antibacterial activity was not affected by differing ethanol concentration in the extraction solvent. The maximum antibacterial activity of ethanolic extract of P. frutescens var. acuta leaf against P. aeruginosa, determined by the EVOP factorial technique, was obtained at an extraction temperature of 80 °C (R = -0.800(**)), 26 h (R = -0.731(**)) extraction time, and 50% (R = -0.075) ethanol concentration. The population of P. aeruginosa also decreased from 6.660 log CFU/mL in the initial set to 4.060 log CFU/mL in the third set. Also, scanning electron microscopy study of the ethanolic extract of P. frutescens var. acuta revealed potential detrimental effects on the morphology of P. aeruginosa.

Hypolipidemic and antioxidant effects of dandelion (Taraxacum officinale) root and leaf on cholesterol-fed rabbits.

Dandelion (Taraxacum officinale), an oriental herbal medicine, has been shown to favorably affect choleretic, antirheumatic and diuretin properties. Recent reports have indicated that excessive oxidative stress contributes to the development of atherosclerosis-linked metabolic syndrome. The objective of this current study was to investigate the possible hypolipidemic and antioxidative effects of dandelion root and leaf in rabbits fed with a high-cholesterol diet. A group of twenty eight male rabbits was divided into four subgroups; a normal diet group, a high-cholesterol diet group, a high-cholesterol diet with 1% (w/w) dandelion leaf group, and a high-cholesterol diet with 1% (w/w) dandelion root group. After the treatment period, the plasma antioxidant enzymes and lipid profiles were determined. Our results show that treatment with dandelion root and leaf positively changed plasma antioxidant enzyme activities and lipid profiles in cholesterol-fed rabbits, and thus may have potential hypolipidemic and antioxidant effects. Dandelion root and leaf could protect against oxidative stress linked atherosclerosis and decrease the atherogenic index.

Preventive Effects of a Probiotic Mixture in an Ovalbumin-Induced Food Allergy Model.

Although there has been a steady increase in the prevalence of food allergies worldwide in recent decades, no effective therapeutic strategies have been developed. Modulation of the gut microbiota composition and/or function through probiotics has been highlighted as a promising target for protection against food allergies. In this study, we aimed to investigate the allergy-reducing effects of a probiotic mixture (P5: Lactococcus lactis KF140, Pediococcus pentosaceus KF159, Lactobacillus pentosus KF340, Lactobacillus paracasei 698, and Bacillus amyloliquefaciens 26N) in mice with ovalbumin (OVA)-induced food allergy. Administration of P5 significantly suppressed the oral OVA challenge-induced anaphylactic response and rectal temperature decline, and reduced diarrhea symptoms. Moreover, P5 also significantly inhibited the secretion of IgE, Th2 cytokines (interleukin (IL)-4, IL-5, IL-10, and IL-13), and Th17 cytokines (IL-17), which were increased in mice with OVA-induced food allergy, and induced generation of CD4+Foxp3+ regulatory T cells. These results revealed that P5 may have applications as a preventive agent against food allergy.

Lactobacillus plantarum Strain Ln4 Attenuates Diet-Induced Obesity, Insulin Resistance, and Changes in Hepatic mRNA Levels Associated with Glucose and Lipid Metabolism.

The prevalence of obesity and associated metabolic disorders, including diabetes and cardiovascular disease, is rapidly becoming a severe global health problem. Recent reports have suggested that the alteration of the gut ecosystem through the consumption of probiotics and fermented foods, such as yogurt and Kimchi, can significantly impact obesity and Type 2 diabetes (T2D)-related biomarkers. In this study, we screened over 400 strains of lactic acid bacteria (LAB) that were isolated from fermented foods to identify potent anti-obesogenic and diabetic probiotics in vitro. Of the strains tested, Lactobacillus plantarum Ln4 (Ln4), which was obtained from napa cabbage kimchi, significantly reduced lipid accumulation and stimulated glucose uptake in 3T3-L1 adipocytes. Oral administration of Ln4 reduced weight gain and epididymal fat mass in mice fed on a high-fat diet (HFD). Total plasma triglyceride level was significantly lower in mice that were treated Ln4 as compared with mice fed HFD. The protein levels of adipokines such as C-reactive protein (CRP), insulin-like growth factor binding proteins-3 (IGFBP-3), and monocyte chemoattractant protein-1 (MCP-1) decreased in white adipose tissues of Ln4-treated mice. Furthermore, these mice exhibited a significant reduction of insulin resistance index (HOMA-IR) and the improvement of glucose tolerance (OGTT) and insulin response (ITT) following Ln4 administration. This was associated with changes in several hepatic gene expressions (increased mRNA levels of IRS2, Akt2, AMPK, LPL, and reduced CD36) that regulate glucose and lipid metabolism. Taken together, these results indicate that in vitro and in vivo Ln4 treatment attenuates diet-induced obesity and T2D biomarkers, highlighting the potential of Ln4 as a therapeutic probiotic agent for metabolic disorders.

Immune-Enhancing Effect of Nanometric Lactobacillus plantarum nF1 (nLp-nF1) in a Mouse Model of Cyclophosphamide-Induced Immunosuppression.

Nanometric Lactobacillus plantarum nF1 (nLp-nF1) is a biogenics consisting of dead L. plantarum cells pretreated with heat and a nanodispersion process. In this study, we investigated the immune-enhancing effects of nLp-nF1 in vivo and in vitro. To evaluate the immunostimulatory effects of nLp-nF1, mice immunosuppressed by cyclophosphamide (CPP) treatment were administered with nLp-nF1. As expected, CPP restricted the immune response of mice, whereas oral administration of nLp-nF1 significantly increased the total IgG in the serum, and cytokine production (interleukin-12 (IL-12) and tumor necrosis factor alpha (TNF-α)) in bone marrow cells. Furthermore, nLp-nF1 enhanced the production of splenic cytokines such as IL-12, TNF-α, and interferon gamma (IFN-γ). In vitro, nLp-nF1 stimulated the immune response by enhancing the production of cytokines such as IL-12, TNF-α, and IFN-γ. Moreover, nLp-nF1 given a food additive enhanced the immune responses when combined with various food materials in vitro. These results suggest that nLp-nF1 could be used to strengthen the immune system and recover normal immunity in people with a weak immune system, such as children, the elderly, and patients.

Next-Generation Sequencing Analyses of Bacterial Community Structures in Soybean Pastes Produced in Northeast China.

Fermented soybean foods contain nutritional components including easily digestible peptides, cholesterol-free oils, minerals, and vitamins. Various fermented soybean foods have been developed and are consumed as flavoring condiments in Asian regions. While the quality of fermented soybean foods is largely affected by microorganisms that participate in the fermentation process, our knowledge about the microorganisms in soybean pastes manufactured in Northeast China is limited. The current study used a culture-independent barcoded pyrosequencing method targeting hypervariable V1/V2 regions of the 16S rRNA gene to evaluate Korean doenjang and soybean pastes prepared by the Hun Chinese (SPHC) and Korean minority (SPKM) populations in Northeast China. In total, 63399 high-quality sequences were derived from 16 soybean paste samples collected in Northeast China. Each bacterial species-level taxon of SPHC, SPKM, and Korean doenjang was clustered separately. Each paste contained representative bacterial species that could be distinguished from each other: Bacillus subtilis in SPKM, Tetragenococcus halophilus in SPHC, and Enterococcus durans in Korean doenjang. This is the 1st massive sequencing-based study analyzing microbial communities in soybean pastes manufactured in Northeast China, compared to Korean doenjang. Our results clearly showed that each soybean paste contained unique microbial communities that varied depending on the manufacturing process and location.