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.

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).

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).

Bacterial community analysis in three types of the fermented seafood, jeotgal, produced in South Korea.

Jeotgal is a traditional Korean seafood fermented by indigenous microbes. The bacterial community in five myeolchi-jeot (Engraulis japonica), five meongge-jeot (Halocynthia roretzi), and six saeu-jeot (Acetes japonicas) produced in South Korea was analyzed by barcoded pyrosequencing targeting the V1/V2 hyper-variable regions of the 16S rRNA gene. All samples were dominated by the phyla Firmicutes, which represented 67.7% (SD = 27.2%) of the population. Tetragenococcus halophilus and Tetragenococcus muriaticus were the predominant species in myeolchi-jeot. The LABs, Lactobacillus sakei, Lactobacillus curvatus, and Weissella koreensis were the predominant species in meongge-jeot. In myeolchi-jeot and meongge-jeot, the bacterial communities within samples were consistent in their predominance, however each of saeu-jeot samples had inter-individual variety in the bacterial community leading to the difficulties of standardization for the commercial production of saeu-jeot. The results of this study will conclusively help to expand our basic knowledge of jeotgal and the related microorganisms involved in food fermentation.

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.

UPLC/ESI-MS/MS analysis of compositional changes for organosulfur compounds in garlic (Allium sativum L.) during fermentation.

In this study, we used liquid chromatography coupled to ion trap mass spectrometry (MS) for the quantification of 11 organosulfur compounds and analysis of their compositional changes in garlic during fermentation using 3 different microbe strains. The calibration curves of all 11 analytes exhibited good linearity (R⩾0.995), and the mean recoveries measured at three concentrations were greater than 81.63% with relative standard deviations of less than 12.79%. Investigation of the compositional changes revealed that the γ-glutamyl peptides content in fermented blanched garlic reduced, whereas the content of the compounds in biosynthesis of S-allyl-l-cysteines from γ-glutamyl peptides increased significantly. Our results also indicated that starter cultures can be used selectively in the production of fermented garlic to increase the amounts of the desired organosulfur compounds.

Bioconversion of Capsaicin by Aspergillus oryzae.

This study identified metabolites of capsaicin bioconverted by Aspergillus oryzae, which is generally used for mass production of gochujang prepared by fermenting red pepper powder in Korea. A. oryzae was incubated with capsaicin in potato dextrose broth. Capsaicin decreased depending on the incubation period, but new metabolites increased. Five capsaicin metabolites purified from the ethyl acetate fraction of the capsaicin culture were identified as N-vanillylcarbamoylbutyric acid, N-vanillyl-9-hydroxy-8-methyloctanamide, ω-hydroxycapsaicin, 8-methyl-N-vanillylcarbamoyl-6(E)-octenoic acid, and 2-methyl-N-vanillylcarbamoyl-6(Z)-octenoic acid by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The capsaicin metabolites in gochujang were confirmed and quantitated by selective multiple reaction monitoring detection after liquid chromatography electrospray ionization MS using the isolated compounds as external standards. On the basis of the structures of the capsaicin metabolites, it is proposed that capsaicin metabolites were converted by A. oryzae by ω-hydroxylation, alcohol oxidation, hydrogenation, isomerization, and α- and/or ß-oxidation.

Bizionia psychrotolerans sp. nov., a psychrophilic bacterium isolated from the intestine of a sea cucumber (Apostichopus japonicus).

A novel Gram-negative, non-flagellated, non-gliding, rod-shaped bacterial strain, designated PB-M7(T), was isolated from the intestine of a sea cucumber collected from Pohang, South Korea. Growth was observed at 4-30 °C (optimum, 25 °C), pH 6.0-9.0 (optimum, pH 7.0-8.0), and with 2.0-6.0% (w/v) NaCl (optimum, 2.0%). In a phylogenetic analysis based on 16S rRNA gene sequences, strain PB-M7(T) was found to belong to the genus Bizionia and to be most closely related to Bizionia echini KMM 6177(T) (99.0% 16S rRNA gene sequence similarity), Bizionia hallyeonensis T-y7(T) (97.9%), Bizionia algoritergicola APA-1(T) (97.5%), Bizionia argentinensis JUB59(T) (97.5%) and Bizionia myxarmorum ADA-4(T) (97.1%). The predominant fatty acids of strain PB-M7(T) were identified as iso-C(15:0) (22.2%), iso-C(15:1) G (10.8%), iso-C(17:0) 3-OH (16.7%) and summed feature 3 (C(16:1) ω7c and/or C(16:1) ω6c; 11.2%). The major respiratory quinone was identified as menaquinone-6 (MK-6). The polar lipid profile of strain PB-M7(T) was found to contain phosphatidylethanolamine, an unidentified phospholipid, three unidentified aminolipids and three unidentified lipids. The DNA G + C content of strain PB-M7(T) was determined to be 33.4 mol% and the mean DNA-DNA relatedness values with the type strains of B. echini, B. hallyeonensis, B. algoritergicola, B. argentinensis, and B. myxarmorum were 52.9, 48.5, 46.5, 37.1 and 26.6%, respectively. Based on the data presented, strain PB-M7(T) represents a novel species of the genus Bizionia, for which the name Bizionia psychrotolerans sp. nov. is proposed. The type strain of B. psychrotolerans is PB-M7(T) (= KCCM 43042 (T) = JCM 19924 (T)).

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.

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.

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.

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%.

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.

Microbial composition of the Korean traditional food "kochujang" analyzed by a massive sequencing technique.

Kochujang is a traditional Korean fermented food that is made with red pepper, glutinous rice, salt, and soybean. Kochujang is fermented by naturally occurring microorganisms through which it obtains various health-promoting properties. In this study, the bacterial diversities of 9 local and 2 commercial brands of kochujang were analyzed with a barcoded pyrosequencing technique targeting the hyper-variable regions V1/V2 of the 16S rRNA gene. Through the analysis of 13524 bacterial pyrosequences, 223 bacterial species were identified, most of which converged on the phylum Firmicutes (average 93.1%). All of the kochujang samples were largely populated (>90.9% of abundance) by 12 bacterial families, and Bacillaceae showed the highest abundance in all but one sample. Bacillus subtilis and B. licheniformis were the most dominant bacterial species and were broadly distributed among the kochujang samples. Each sample contained a high abundance of region-specific bacterial species, such as B. sonorensis, B. pumilus, Weissella salipiscis, and diverse unidentified Bacillus species. Phylotype- and phylogeny-based community comparison analysis showed that the microbial communities of the two commercial brands were different from those of the local brands. Moreover, each local brand kochujang sample had region-specific microbial community reflecting the manufacturing environment.