Lactobacillus pentosus SMB718 as a probiotic starter producing allyl mercaptan in garlic and onion-enriched fermentation.

Fermenting garlic and onion provides the advantages of storage life extension, anti-oxidative and anti-diabetic activities, and their metabolite, allyl mercaptan, offers a strong aroma and various health benefits. Here, we report the probiotic properties of Lactobacillus pentosus SMB718 isolated from Korean traditional paste and its high allyl mercaptan productivity in garlic and onion fermentation. This strain was safe for use in food fermentation, as it was a non-biogenic amine producer and non-hemolytic. It showed high stability under simulated human gastrointestinal conditions and good adhesion ability to intestinal epithelial cells, including both Caco-2 and HT-29. This strain had antioxidant and anti-microbial activities. In addition, the heat-killed cells and lysate exerted anti-inflammatory effects on both LPS-stimulated RAW 264.7 cells and mouse macrophages by inhibition of pro-inflammatory cytokines and induction of anti-inflammatory cytokines. Furthermore, this strain possessed good fermentation properties in garlic and onion-enriched radish juice (GORJ); it grew well decreasing the pH and provided a rich aroma compound during fermentation. When L. pentosus SMB718 was used as a starter in garlic and onion fermentation, a significantly higher amount of allyl mercaptan (344 ppb) was produced compared with that produced by the type strain (82 ppb). In conclusion, L. pentosus SMB718 can be used as a beneficial probiotic starter for better flavor production in the fermentation of allium species plants.

Anti-Inflammatory and Skin-Moisturizing Effects of a Flavonoid Glycoside Extracted from the Aquatic Plant Nymphoides indica in Human Keratinocytes.

Nymphoides indica, an aquatic plant, is used as folk medicine in some countries. Our previous study demonstrated that the methanol extract of N. indica inhibited the activity of tyrosinases, tyrosine related protein (TRP)1 and TRP2, and microphthalmia-associated transcription factor, as well as the activity of protein kinase A, by effectively inhibiting cyclic adenosine monophosphate. Although the biological activities of N. indica extract have been reported, there are no reports on the skin bioactivity of the main compound(s) on human keratinocytes. This study investigated the anti-inflammatory and moisturizing effects of quercetin 3,7-dimethyl ether 4'-glucoside (QDG) isolated from N. indica. In brief, ultraviolet B irradiated keratinocytes were pretreated with different concentrations of QDG, and the effects of QDG on various inflammatory markers were determined. QDG significantly inhibited inflammation-related cytokines and chemokines and enhanced the activation of skin barrier factors. Additionally, QDG also attenuated phosphorylation inhibition of the upstream cytokines and nuclear factor-κB expression. These results suggest that QDG isolated from N. indica may serve as a potential source of bioactive substances for chronic inflammatory skin diseases.

Performance of a segmented HPGe detector at KRISS.

A 24 segmented HPGe coaxial detector was set up with a digitized data acquisition system (DAQ). The DAQ was composed of a digitizer (5 × 107sampling/s), a Field-Programmable Gate Array (FPGA), and a real time operating system. The Full Width Half Maximum (FWHM), rise time, signal characteristics, and spectra of a 137Cs source were evaluated. The data were processed using an in-house developed gamma-ray tracking system.

Clarification of the calculation of minimum detectable activity in low-level radioactivity measurements.

We discuss a new method to determine the value of minimum detectable activity (MDA) in low-level measurements. The method is based on the Feldman-Cousins unified approach which effectively combines the construction of confidence intervals with the determination of the decision threshold and MDA. The new method requires a single probability to be pre-specified for the determination of MDA as well as decision threshold and confidence interval, in contrast with the ISO 11929 method requiring three probabilities.

New method to incorporate Type B uncertainty into least-squares procedures in radionuclide metrology.

We discuss a new method to incorporate Type B uncertainty into least-squares procedures. The new method is based on an extension of the likelihood function from which a conventional least-squares function is derived. The extended likelihood function is the product of the original likelihood function with additional PDFs (Probability Density Functions) that characterize the Type B uncertainties. The PDFs are considered to describe one's incomplete knowledge on correction factors being called nuisance parameters. We use the extended likelihood function to make point and interval estimations of parameters in the basically same way as the least-squares function used in the conventional least-squares method is derived. Since the nuisance parameters are not of interest and should be prevented from appearing in the final result, we eliminate such nuisance parameters by using the profile likelihood. As an example, we present a case study for a linear regression analysis with a common component of Type B uncertainty. In this example we compare the analysis results obtained from using our procedure with those from conventional methods.

A preliminary study for the development of reference material using oyster for determination of (137)Cs, (90)Sr and plutonium isotopes.

A new reference material for the determination of (137)Cs, (90)Sr and Pu isotopes ((238)Pu and (239,240)Pu) is being developed using dried oyster matrix by Korea Research Institute of Standards and Science (KRISS). The oyster was collected from Tongyoung harbour, southern part of Korea and the artificial radionuclides ((137)Cs, (90)Sr, (238)Pu and (239,240)Pu) were spiked into the material. After pretreatment and processing, the material was tested for homogeneity and massic activities were determined by measuring (137)Cs, (90)Sr, (238)Pu and (239,240)Pu. The reference value and extended uncertainty for those isotopes will be reported later.

Nitrospirillum irinus sp. nov., a diazotrophic bacterium isolated from the rhizosphere soil of Iris and emended description of the genus Nitrospirillum.

A polyphasic approach was used to characterize a novel nitrogen-fixing bacterial strain, designated YC6995(T), isolated from the rhizosphere soil of Iris ensata var. spontanea (Makino) Nakai inhabiting a wetland located at an altitude of 960 m on Jiri Mountain, Korea. Strain YC6995(T) cells were Gram-negative, and rod-shaped, with motility provided by a single polar flagellum. Optimal growth conditions were 30 °C and pH 7.0. The major fatty acids of strain YC6995(T) were C18:1 ω7c, C18:1 2-OH and C16:0 3-OH. The major respiratory quinone was ubiquinone-10 (Q-10). The polar lipids were phosphatidylethanolamine, phosphatidyldimethylethanolamine, phosphatidylcholine, phosphatidylglycerol and unidentified glycolipids. The genomic DNA G+C content was 64.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed strain YC6995(T) to form a phyletic lineage with Nitrospirillum amazonense DSM 2787(T) with a high sequence similarity (97.2 %), but it displayed low sequence similarity with other remotely related genera, including Azospirillum (<93 %), Rhodocista (93.1-93.4 %), and Skermanella (91.2-93.3 %) in the family Alphaproteobacteria. Based on the phenotypic, chemotaxonomic, and phylogenetic evidences, strain YC6995(T) represents a novel species within the genus Nitrospirillum, for which the name Nitrospirillum irinus sp. nov. is proposed. The type strain is YC6995(T) (= KACC 13777(T) = DSM 22198(T)). An emended description of the genus Nitrospirillum is also proposed.

Atmospheric input of ¹³7Cs and 239,240Pu isotopes in Korea after the Fukushima nuclear power plant accident.

Caesium isotopes ((134)Cs and (137)Cs) and (239,240)Pu in rainwater and dry deposition have been analyzed by Korea Research Institute of Standards and Science (KRISS) since the Fukushima nuclear power plant (NPP) accident in March 2011. The concentrations of (239,240)Pu and (137)Cs in the rainwater are 2.6±1.0 to 15±3 µBq/kg and 0.01 to 0.36 mBq/kg, respectively. The concentrations are concordant to those observed before the Fukushima NPP accident, on the other hand, the monthly depositional flux of (239,240)Pu and (137)Cs are much lower than the amounts observed after Fukushima NPP accident and in Monaco in 1998-2001. This confirms that the Fukushima NPP accident caused no significant impact in Korea.

Realization of radioactive equilibrium in the KRISS radon chamber.

The maintenance of radioactive equilibrium between radon and its decay products in a radon chamber is necessary to calibrate radon decay product monitors. In this study, the activity concentrations of radon decay products have been measured, and mosquito-repellent incense has been used to produce aerosol particles in the chamber. Filter papers with 8 µm pore size were used to collect aerosol in the chamber. The activity concentrations of radon decay products have been evaluated by the Modified Tsivoglou Method. The correction factors due to the differences in counting time requirements of the Modified Tsivoglou Method and the time delay between consecutive measurements have been determined. Finally, the radioactive equilibrium has been confirmed by applying the Bateman equation.

New method to determine the decision threshold for low-level radioactivity measurements.

We discuss a new method to determine the value of a decision threshold that can be used to decide whether to choose a one-sided confidence interval or a two-sided confidence interval. The method is based on the Feldman-Cousins unified approach providing a unique confidence region for estimated parameters. We apply this method to a net count rate measurand in low-level radioactivity measurements which is physically restricted to nonnegative values. We tabulate the values of the decision threshold and detection limit of the measurand for some typical coverage probabilities. The decision threshold in this method does indeed enable a decision on whether or not the physical effect quantified by the measurand is present.

Enzymatic synthesis of puerarin glucosides using Leuconostoc dextransucrase.

Puerarin (P), an isoflavone derived from kudzu roots, has strong biological activities, but its bioavailability is often limited by its low water solubility. To increase its solubility, P was glucosylated by three dextransucrases from Leuconostoc or Streptococcus species. Leuconostoc lactis EG001 dextransucrase exhibited the highest productivity of puerarin glucosides (P-Gs) among the three tested enzymes, and it primarily produced two P-Gs with a 53% yield. Their structures were identified as alpha-D-glucosyl-(1-->6)-P (P-G) by using LC-MS or (1)H- or (13)C-NMR spectroscopies and alpha-D-isomaltosyl-(1-->6)-P (P-IG2) by using specific enzymatic hydrolysis, and their solubilities were 15- and 202-fold higher than that of P, respectively. P-G and P-IG2 are easily applicable in the food and pharmaceutical industries as alternative functional materials.

Biochemical characterization of thermophilic dextranase from a thermophilic bacterium, Thermoanaerobacter pseudethanolicus.

TPDex, a putative dextranase from Thermoanaerobacter pseudethanolicus, was purified as a single 70 kDa band of 7.37 U/mg. Its optimum pH was 5.2 and the enzyme was stable between pH 3.1 and 8.5 at 70 degrees C. A half-life comparison showed that TPDex was stable for 7.4 h at 70 degrees C, whereas Chaetominum dextranase (CEDex), currently used as a dextranase for sugar milling, was stable at 55 degrees C. TPDex showed broad dextranase activity regardless of dextran types, including dextran T2000, 742CB dextran, and alternan. TPDex showed the highest thermostability among the characterized dextranases, and may be a suitable enzyme for use in sugar manufacture without decreased temperature.

Standardization of 18F by digital coincidence counting.

The radioactivity of (18)F has been measured by a digital coincidence counting (DCC) system. The main advantages of the digital coincidence counting technique are a shortening of the measurement time as compared with conventional coincidence counting and an ability to obtain activities with various experimental parameters through off-line analysis. The measurement results of radioactivity for (18)F solution were compared with those of a conventional coincidence counting technique and a reference ion chamber method.

Mass production of rubusoside using a novel stevioside-specific ß-glucosidase from Aspergillus aculeatus.

Rubusoside (R) is a natural sweetener and a solubilizing agent with antiangiogenic and antiallergic properties. However, currently, its production is quite expensive, and therefore, we have investigated nine commercially available glycosidases to optimize an economically viable R-production method. A stevioside (ST)-specific ß-glucosidase (SSGase) was selected and purified 7-fold from Aspergillus aculeatus Viscozyme L by a two-step column chromatography procedure. The 79 kDa protein was stable from pH 3.0 to pH 7.0 at 50-60 °C. Hydrolysis of ST by SSGase produced R and steviol monoglucosyl ester as determined by (1)H and (13)C nuclear magnetic resonance (NMR). Importantly, SSGase showed higher activity toward ST than other ß-linked glucobioses. The optimal conditions for R production were 280 mM ST and 16.6 µL of SSGase at pH 5.1 and 63 °C. This is the first discussion detailing the production of R by enzymatic hydrolysis of ST and is useful for the food additive and pharmaceutical industries.

Calibration of KRISS reference ionization chamber for key comparison of (99m)Tc measurement.

KRISS, as the national metrology institute of Korea, has used a reference ionization chamber system to certify the activity of (99m)Tc aqueous sources, but could only recently participate in a comparison exercise by the BIPM (BIPM.RI(II)-K4.Tc-99m) to secure the international equivalence of (99m)Tc radioactivity measurement by way of the BIPM transfer instrument (SIRTI). The KRISS ionization chamber system was calibrated about 100 days before the comparison with a (99m)Tc solution source standardized by the 4πß(LS)-γ(NaI(Tl)) coincidence counting method. During the comparison, beginning with a higher activity mother solution, the KRISS ionization chamber measured its specific activity without a dilution. The activity of a diluted-solution source was measured by the SIRTI at the same time.

Chitinophaga oryziterrae sp. nov., isolated from the rhizosphere soil of rice (Oryza sativa L.).

A novel bacterial strain, YC7001(T), was isolated from the rhizosphere soil of rice collected at Jinju, Korea, and was characterized using a polyphasic approach. Cells of strain YC7001(T) were Gram-negative-staining, yellow-pigmented, rod-shaped, aerobic, heterotrophic and non-motile. Strain YC7001(T) grew optimally at 25-30 °C, pH 5.0-8.0 and degraded gelatin, cellulose and chitin. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain YC7001(T) belonged to the genus Chitinophaga in the family Chitinophagaceae. The most closely related species were Chitinophaga sancti NBRC 15057(T) (96.9%), Chitinophaga ginsengisoli Gsoil 052(T) (95.9%), Chitinophaga pinensis DSM 2588(T) (95.7%), Chitinophaga filiformis IFO 15056(T) (95.7%) and Chitinophaga niabensis JS13-10(T) (95.0%). The DNA-DNA relatedness value of strain YC7001(T) with C. sancti NBRC 15057(T) was 15.2 ± 0.6%. Strain YC7001(T) contained MK-7 as the major menaquinone and homospermidine as the major polyamine. The major fatty acids of strain YC7001(T) were C(15:0) iso, C(16:1)ω5c and C(17:0) iso 3-OH. The polar lipids were phosphatidylethanolamine, unknown aminolipids and unknown lipids. The total genomic DNA G+C content was 41.3 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic analyses, strain YC7001(T) represents a novel species of the genus Chitinophaga, in the family Chitinophagaceae, for which the name Chitinophaga oryziterrae sp. nov. is proposed. The type strain is YC7001(T) ( = KACC 14533(T) = JCM 16595(T)).

Plantar fasciitis (fasciosis) treatment outcome study: plantar fascia thickness measured by ultrasound and correlated with patient self-reported improvement.

Ultrasound, well recognized as an effective diagnostic tool, reveals a thickening of the plantar fascia in patients with plantar fasciitis/fasciosis disease. The authors hypothesized that ultrasound would also reveal a decrease in the plantar fascia thickness for patients undergoing treatment for the disease, a hypothesis that, heretofore, had been only tested on a limited number of subjects. They conducted a more statistically significant study that found that clinical treatment with injection and biomechanical correction does indeed diminish plantar fascia thickness as shown on ultrasound. The study also revealed that patients experience the most heightened plantar fascia tenderness toward the end of the day, and improvement in their symptomatic complaints were associated with a reduction in plantar fascia thickness. As a result, the authors conclude that office-based ultrasound can help diagnose and confirm plantar fasciitis/fasciosis through the measurement of the plantar fascia thickness. Because of the advantages of ultrasound--that it is non-invasive with greater patient acceptance, cost effective and radiation-free--the imaging tool should be considered and implemented early in the diagnosis and treatment of plantar fasciitis/fasciosis.

Construction of classical confidence regions of model parameters in nonlinear regression analyses.

Feldman-Cousins' unified approach provides an unique confidence region for parameters under estimation and assures an exact coverage for the constructed confidence region. We present a procedure to implement this approach in least-squares regression analyses. The procedure is based on a series of the most powerful likelihood-ratio tests of hypothesis using a single number as a test statistic. The procedure thereby avoids the complications of the Feldman-Cousins method arising when the number of free parameters is more than one. Applying the procedure to a case of nonlinear regression problems where the estimated parameters are not generally Gaussian distributed, we show that one has to use the procedure when the results of the regression analysis are to be carefully investigated near a boundary of the physical region.