• Journal of Microbiology and Biotechnology
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• v.25 no.9
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• pp.1519-1527
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• 2015

Biogenic amines in some food products present considerable toxicological risks as potential human carcinogens when consumed in excess concentrations. In this study, we investigated the degradation of the biogenic amines histamine and tyramine and the presence of genes encoding histidine and tyrosine decarboxylases and amine oxidase in Bacillus species isolated from fermented soybean food. No expression of histidine and tyrosine decarboxylase genes (hdc and tydc) were detected in the Bacillus species isolated (B. subtilis HJ0-6, B. subtilis D'J53-4, and B. idriensis RD13-10), although substantial levels of amine oxidase gene (yobN) expression were observed. We also found that the three selected strains, as non-biogenic amineproducing bacteria, were significantly able to degrade the biogenic amines histamine and tyramine. These results indicated that the selected Bacillus species could be used as a starter culture for the control of biogenic amine accumulation and degradation in food. Our study findings also provided the basis for the development of potential biological control agents against these biogenic amines for use in the food preservation and food safety sectors.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2732-2736
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• 2011

In pH 4.2 HAc-NaAc buffer solution, horseradish peroxidase (HRP) catalyzed $H_2O_2$ oxidation of nanosilver to form $Ag^+$. After centrifugation, $Ag^+$ in the supernatant can be measured by graphite furnace atomic absorption spectrophotometry (GFAAS) at the silver absorption wavelength of 328.1 nm. When HRP concentration increased, the $Ag^+$ concentration in the supernatant increased, and the absorption value enhanced. The HRP concentration in the range of 0.84-50 $ng{\cdot}mL^{-1}$ was linear to the enhanced absorption value (${\Delta}A$), with a regression equation of ${\Delta}A$=0.012C+0.11, correlation coefficient of 0.9988, and detection limit of 0.41 $ng{\cdot}mL^{-1}$ HRP. The proposed GFAAS method was used to detect HRP in waste water samples, with satisfactory results.

• Journal of Environmental Science International
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• v.27 no.4
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• pp.275-279
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• 2018

Water status of intact plants has been optically estimated by measuring reflectance at the wavelengths 1,450 nm and 1,900 nm based on their signal strengths. Although another water band at 970 nm is considered to have very small signals, the band apparently lies within the detection range of inexpensive spectrometer and plain charge-coupled device (CCD) camera used in wild fire studies. However measurement of the reflectance at 970 nm has been rarely applied to estimate the water status of dead plant materials such as fallen branch, twig, and leaf. To test the possibility of applying water reflectance at 970 nm to estimate the water content (WC) in leaf litter, the reflectance in various WC values were measured in the leaf litter of three Quercus species (Q aliena, Q aliena, Q mongolica, and Quercus variabilis). The results showed that the WC in the leaf litter can be determined by reflectance water index (WI) in the three Quercus species ($WC=1,450{\times}WI-1,378.8$, r=0.865). However, there was no interaction effect in the relationship between WI and WC among the litter of the three Quercus species.

• Korean Journal of Materials Research
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• v.27 no.5
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• pp.255-262
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• 2017

Reactive oxygen species (ROS) can be produced by interactions between sunlight and light-absorbing substances in natural water environments and can completely destroy various organic pollutants in waste water. In this study, we used graphene oxide modified $Ag_2Se$ nanoparticles to enhance photochemically generated oxygen (PGO) species activity. Surface area and pore volumes of the $Ag_2Se-graphene$ ($Ag_2Se-G$) samples showed catastrophic decrease due to deposition of $Ag_2Se$. The generation of reactive oxygen species was detected through the oxidation reaction of DPCI to DPCO. The photocurrent density and the PGO effect increase in the case of the use of modified graphene. The PGO effect of the graphene modified with $Ag_2Se$ composites increased significantly due to a synergetic effect between graphene and the $Ag_2Se$ nanoparticles. The photocatalytic activity of sample was evaluated by measuring the degradation of organic pollutants such as methylene blue (MB) and industrial dyes such as Texbrite BA-L (TBA) under visible light.

• Journal of the korean society of oceanography
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• v.34 no.3
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• pp.167-171
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• 1999

Since toxic Alexandrium catenella and non-toxic A. fraterculus are morphologically similar, they are difficult to discriminate under the light microscope. However, a novel technology, such as fluorescein isothiocyanate (FITC)-conjugated lectin probes enables easy and rapid differentiation. Toxic A. catenella bound seven different lectins, whereas the non-toxic A. fratercuzus did not bind Arachis hypogaea (PNA) lectin. In addition, Pseudo-nitrschia species in this study were also difficult to identify to species level with light microscope techniques, but it was possible to classify them using fluorescent lectins. Pseudo-nitzschia multistriata, P. subfraudulenta and P. pungens bound Canavalia ensiformis (ConA), whereas P. subpaclfica did not, and P. pungens also bound Ricinus communis (RCA). These results imply that lectin could be used as a critical tool in the differentiation of P. multistriata, P. subfraudulenta and P. pungens. However, P. subpacifica was not differentiated by the lectins tested. Therefore, it isconcluded that lectin probes are useful for discriminating toxic A. catenella from non-toxic A. fraterculus, and for the identification of some Pseudo-nitzschia species. In addition, this method has a great potential to speed and detection between non-toxic and toxic harmful algal blooms (HABs) in Korean biotoxin monitoring systems.

• Ocean and Polar Research
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• v.38 no.1
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• pp.35-46
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• 2016

To understand the diet of chaetognaths, the gut content and fatty acid trophic makers (FATMs) of Sagitta crassa and S. nagae, which are the most predominant species of chaetognath in the Yellow Sea, were analyzed. Gut contents of the two species examined by microscopic analysis revealed that copepods are the major components of the diet (> 70% of gut contents) and there was no significant changes in the gut contents of two species collected in spring and summer season. Although 16:0, 20:5(n-3) (Eicosapentaenoic acid) and 22:6(n-3) (Docosahexanoic acid), which are known as phytoplankton FA markers, were the most dominant among the fatty acids in both chaetognath species, the detection of copepod FA markers, 20:1(n-9) (Gadoleic acid) and 22:1(n-11) (Cetoleic acid), provided evidence that their food sources include copepods. These results suggest that S. crassa and S. nagae are carnivores and mainly feed on copepods in the Yellow Sea.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.3
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• pp.158-165
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• 2006

Although Mycobacterium tuberculosis complex strains remain responsible for the majority of diseases caused by mycobacterial infections worldwide, the increase in HIV infections has allowed for the emergence of other non-tuberculous mycobacteria as clinically significant pathogens. However, Mycobacterium species has a long period of incubation, and requires serious biochemical tests such as niacin, catalase, and nitrate test that are often tedious. The development of rapid and accurate diagnostics can aid in the early diagnosis of disease caused by Mycobacterium. The current DNA amplification and hybridization methods that have been developed target several genes for the detection of mycobacterial species such as hps65, 16S rDNA, rpoB, and dnaj. These methods produce rapid and accurate results. In this study, PCR-restriction fragment length polymorphism analysis(PCR-RFLP) based on the region of the rpoB gene was used to verify the identification of non-tuburculosis Mycobacterium species. A total of 8 mycobacterial reference strains and 13 clinical isolates were digested with restriction enzymes such as Msp I in this study. The results of using this process clearly demonstrated that all 13 specimens were identified by rpoB gene PRA method. The PCR-RFLP method based on the rpoB gene is a simple, rapid, and accurate test for the identification of Mycobacterium.

• Natural Product Sciences
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• v.16 no.1
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• pp.39-42
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• 2010

The content of hyperin in Acanthopanax species was determined by high performance liquid chromatography (HPLC). Hyperin was quantified by a reverse-phase column with elution program [initially gradient solvent (acetonitrile : water = 85 : 15 to 80 : 20 for 20 min), then isocratic solvent (acetonitrile : water = 80 : 20 for 20 min), and finally gradient solvent (acetonitrile : water = 80 : 20 to 65 : 35 for 20 min)]. UV detection was conducted at 210 nm. The content of hyperin in the fruits of Acanthopanax was measured in the species A. chiisanensis (2.04 mg/g), A. sessiliflorus (1.13 mg/g), A. divaricatus (0.98 mg/g), A. koreanum (0.75 mg/g) and A. senticosus (0.05 mg/g). The content of hyperin in A. chiisanensis was higher than that of other Acanthopanax species.

• Journal of Preventive Veterinary Medicine
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• v.41 no.3
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• pp.121-123
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• 2017

The hepatitis E virus (HEV) is a leading causative agent of acute hepatitis in humans. Zoonotic HEV strains have been isolated from several animal species, including pigs. New HEV variants have been recently isolated from camels in the Middle East. In the present study, fecal samples from fallow deer, formosan deer, alpaca, and guanaco were analyzed for the detection of HEV. One HEV strain was detected from guanaco, a species of camelids. The nucleotide sequence of guanaco HEV was identical to those of deer HEV-3 strains, which implied the cross-species transmission of HEV-3 from deer to guanaco.

• Journal of Forest and Environmental Science
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• v.35 no.3
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• pp.181-188
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• 2019

This study was performed to construct tree species classification map according to three information types (spectral information, texture information, and spectral and texture information) by altitude (30 m, 60 m, 90 m) using the unmanned aerial vehicle images and the object-based classification method, and to evaluate the concordance rate through field survey data. The object-based, optimal weighted values by altitude were 176 for 30 m images, 111 for 60 m images, and 108 for 90 m images in the case of Scale while 0.4/0.6, 0.5/0.5, in the case of the shape/color and compactness/smoothness respectively regardless of the altitude. The overall accuracy according to the type of information by altitude, the information on spectral and texture information was about 88% in the case of 30 m and the spectral information was about 98% and about 86% in the case of 60 m and 90 m respectively showing the highest rates. The concordance rate with the field survey data per tree species was the highest with about 92% in the case of Pinus densiflora at 30 m, about 100% in the case of Prunus sargentii Rehder tree at 60 m, and about 89% in the case of Robinia pseudoacacia L. at 90 m.