• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.183-188
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• 1999

The incidence of Yersinia enterocolitica in raw meat was determined over 10 month period. Y. enterocolitica was isolated from 8.5% of beef, 17.0% of pork and 25.6% of chicken. Overall prevalence of Y. enterocolitica in raw meat was 17.5%. Seasonal difference was observed in isolation rate in which pork and chicken samples collected in the second half of the year twice was more than that of the first half of the year. Serotypes of Y. enterocolitica isolates were O:5 (17.3%), O:8 (8.6%), O:3 (6.2%), O:1,2 (1.2%), and others. The antibiotics susceptibility tests showed Y. enterocolitica isolates were resistant to carbenicillin, ampicillin, erythromycin, penicillin and bacitracin. In contrast it showed sensitivity to polymyxin B, kanamycin, ciprofloxacin, gentamicin, trimethoprim/sulfamethoxazole, nalidixic acid, and tetracycline. PCR with specific primers derived from ail gene of Y. enterocolitica was applied to detect and confirm pathogenic Y. enterocolitica. About 10% of the isolated Y. enterocolitica proved to be pathogenic and most of them were found in pork. However, proper cooking and meat process can kill and remove all Y. enterocolitica in meat, because the organism is very sensitive to heat.

• Horticultural Science & Technology
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• v.29 no.6
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• pp.511-522
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• 2011

Flower color is one of the main target traits in the flower breeding. Recently, technological advances in genetic engineering have been successfully reported the flower colors, such as blue roses and blue carnations that are impossible to develop by traditional breeding. Accumulated knowledge-based approaches for flavonoid biosynthesis enabled to introduce novel and unique colors into flowers. These flower color modifications have been made through the regulation of flavonoid metabolic pathway - control of endogenous gene expression and introduction of foreign genes to produce novel and specific flavonoids - and the introduction of transcription factors that are known to regulate sets of genes being involving in the flavonoid biosynthetic pathway. More empirical regulation of the flavonoids metabolism requires the understanding for regulatory mechanism of intrinsic flavonoids depending on the flower crops and the very sophisticated control of flavonoid metabolic flow. In this review, we summarized successful examples of flower color modification. It might be useful to deduce the strategy for the creation of exquisite colors in flower plants.

• Journal of KIISE:Software and Applications
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• v.34 no.12
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• pp.1056-1064
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• 2007

Biomolecular computing is a new computing paradigm that uses biomolecules such as DNA for information representation and processing. The huge number of molecules in a small volume and the innate massive parallelism inspired a novel computation method, and various computation models and molecular algorithms were developed for problem solving. In the meantime, the use of biomolecules for information processing supports the possibility of DNA computing as an application for biological problems. It has the potential as an analysis tool for biochemical information such as gene expression patterns. In this context, a DNA computing-based model of a biomolecular perceptron has been proposed and the result of its experimental implementation was presented previously. The weight encoding and weighted sum operation, which are the main components of a biomolecular perceptron, are based on the competitive hybridization reactions between the input molecules and weight-encoding probe molecules. However, thermodynamic symmetry in the competitive hybridizations is assumed, so there can be some error in the weight representation depending on the probe species in use. Here we suggest a generalized model of hybridization reactions considering the asymmetric thermodynamics in competitive hybridizations and present a weight encoding method for the reliable implementation of a biomolecular perceptron based on this model. We compare the accuracy of our weight encoding method with that of the previous one via computer simulations and present the condition of probe composition to satisfy the error limit.

• Journal of Microbiology and Biotechnology
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• v.11 no.6
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• pp.915-921
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• 2001

Phytase improves the bioavailability of phytate phosphorus in plant foods to humans and animals, and reduces the phosphorus pollution of animal waste. In order to express a high level of fungal phytase in Saccharomyces cerevisiae, various expression vectors were constructed with different combinations of promoters, translation enhancers, signal peptides, and terminator. Three different promoters fused to the phytase gene (phyA) from Aspergillus niger were tested: a galactokinase (GAL1) promoter, glyceraldehyde-3-phosphate dehydrogenase (GPD) promoter, and yeast hybrid ADH2-GPD promoter consisting of alcohol dehydrogenase II (ADH2) and a GPD promoter. The signal peptides of phytase, glucose oxidase (GO), and rice amylase 1A(RAmy1A) were included. Plus, the translation enhancers of the ${\Omega}$ sequence and UTR70 from the tobacco mosaic virus (TMV) and spinach, respectively, were also tested. Among the recombinant vectors, pGphyA06 containing the GPD promoter, the ${\Omega}$ sequence, RAmy1A, and GAL7 terminator expressed the highest phytase activity in a culture filtrate, which was estimated at 20 IU/ml. An intracellular localization of the expressed phytase activity in a culture filtrate, which was estimated at 20 IU/ml. An intracellular localization of the expressed phytase was also performed by inserting an endoplasmic reticulum (ER) retention signal, KDEL sequence, into the C-terminus of the phytase within the vector pHphyA-6. It appeared that the KDEL sequence directed most of the early expression of phytase into the intracellular compartment yet more than $60\%$ of the total phytase activity was still retained within the cell even after the prolonged (>3 days) incubation of the transformant. However, the intracellular enzyme activity of the transformant without a KDEL sequence was as high as that of the extracellular one, thereby strongly suggesting that the secretion of phytase in S. cerevisiae appeared to be the rate-limiting step for the expression of a large amount of extracellular recombinant phytase, when compared with other yeasts.

• Microbiology and Biotechnology Letters
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• v.34 no.1
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• pp.58-62
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• 2006

Rapid assay of enzyme is a primary requirement for successful application of directed evolution technology. Halo generation on a turbid plate would be a method of choice for high throughput screening of enzymes in this context. Here we report a new approach to prepare turbid plates, by controlling the crystallization of tyrosine to form needle-like particles. In the presence of tyrosine phenol-lyase (TPL), the needle-like tyrosine crystals were converted to soluble phenol rapidly than the usual rectangular tyrosine crystals. When an error-prone PCR library of Citrobacter freundii TPL was spread on the turbid plate, approximately 10% of the colonies displayed recognizable halos after 24 hours of incubation at $37^{\circ}C$. Representative positives from the turbid plates were transferred to LB-medium in 96-wellplates, cultivated overnight, and assayed for the enzyme activity with L-tyrosine as the substrate. The assay results were approximated to be proportional to the halo size on turbid plates, suggesting the screening system is directly applicable to the directed evolution of TPL. Actually, two best mutants on the turbid plates were identified to be $2{\sim}2.5$ and 1.5-fold improved in the activity.

• Microbiology and Biotechnology Letters
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• v.44 no.1
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• pp.26-33
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• 2016

Dominant lactic acid bacteria (LAB) strains were isolated from traditional fermented foods to obtain rare ${\gamma}$-aminobutyric acid (GABA)-producing LAB. Out of 147 isolates, 23 strains that could produce GABA with 1% (w/v) L-monosodium glutamate (MSG) were first isolated. After further screening of these rare GABA-producing LAB by analysis of the glutamate decarboxylase and 16S rRNA gene sequences, Enterococcus faecium JK29 was isolated, and 1.56 mM of GABA was produced after 48 h cultivation in basic de Man, Rogosa, and Sharpe (MRS) medium. To enhance GABA production by E. faecium JK29, the culture conditions were optimized. When E. faecium JK29 was cultivated in optimized MRS medium containing 0.5% (w/v) sucrose and 2% (w/v) yeast extract with 0.5% (w/v) MSG, GABA production reached 14.86 mM after 48 h cultivation at initial conditions of pH 7.5 and $30^{\circ}C$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.294-302
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• 2020

In a genetic algorithm, computer simulations are performed based on the natural evolution process of life, such as selection, crossover, and mutation. The genetic algorithm searches the approximate optimal solution by the parallel arrangement of Schema, which has a short definition length, low order, and high adaptability. This study examined the possibility of improving the efficiency of the optimal solution by considering the characteristics of the building block hypothesis, which are one of the key operating principles of a genetic algorithm. This study evaluated the efficiency of the optimization results according to the gene sequence for the implementation in solving problems. The optimal design problem of the water pipe was selected, and the genetic arrangement order reflected the engineering specificity by dividing into the existing, the network topology-based, and the flowrate-based arrangement. The optimization results with a flowrate-based arrangement were, on average, approximately 2-3% better than the other batches. This means that to increase the efficiency of the actual engineering optimization problem, a methodology that utilizes clear prior knowledge (such as hydraulic properties) to prevent such excellent solution characteristics from disappearing is essential. The proposed method will be considered as a tool to improve the efficiency of large-scale water supply network optimization in the future.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2747-2751
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• 2014

Background: DNA repair pathways play a crucial role in maintaining the human genome. Previous studies associated DNA repair gene polymorphisms (XPD Lys751Gln, XRCC1 Arg280His and XRCC1 Arg399Gln) with nasopharyngeal carcinoma. These non-synonymous polymorphisms may alter DNA repair capacity and thus increase or decrease susceptibility. The present study aimed to determine the genotype distribution of XPD codon 751, XRCC1 codon 280 and codon 399 polymorphisms and haplotype associations among NPC cases and controls in the Malaysian population. Materials and Methods: We selected 157 NPC cases and 136 controls from two hospitals in Kuala Lumpur, Malaysia for this study. The polymorphisms studied were genotyped by PCR-RFLP assay and allele and genotype frequenci es, haplotype and linkage disequilibrium were determined using SNPstat software. Results: For the XPD Lys751Gln polymorphism, the frequency of the Lys allele was higher in cases than in controls (94.5% versus 85.0%). For the XRCC1 Arg280His polymorphism, the frequency of Arg allele was 90.0% and 89.0% in cases and controls, respectively and for XRCC1 Arg399Gln the frequency of the Arg allele was 72.0% and 72.8% in cases and controls respectively. All three polymorphisms were in linkage disequilibrium. The odds ratio from haplotype analysis for these three polymorphisms and their association with NPC was 1.93 (95%CI: 0.90-4.16) for haplotype CGC vs AGC allele combinations. The global haplotypte association with NPC gave a p-value of 0.054. Conclusions: Our study provides an estimate of allele and genotype frequencies of XRCC1Arg280His, XRCC1 Arg399Gln and XPD Lys751Gln polymorphisms in the Malaysian population and showed no association with nasopharyngeal cancer.

• Clinical and Experimental Pediatrics
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• v.45 no.3
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• pp.413-417
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• 2002

Gitelman's syndrome is an autosomal recessive disorder characterized by hypokalemic metabolic alkalosis, hypomagnesemia, and hypocalciuria that has recently been reported to be linked to thiazide- sensitive Na-Cl cotransporter gene mutation. In this study, we performed renal clearance studies to differentiate Gitelman's from Bartter's syndrome and to confirm the diagnosis in two patients clinically diagnosed with Gitelman's syndrome. Each patient was hydrated by 20 mL/kg body weight of oral water within 30 minutes, which was followed by intravenous half saline. When urinary flow reached 10 mL/min, samples of urine and serum were obtained to calculate the osmolar clearance, free water clearance, chloride clearance, and distal fractional chloride reabsorption. Subsequently, furosemide or hydrochlorothiazide was administered. Samples were collected and the same parameters were calculated. In our patients, chloride clearance was increased more than 10 times after furosemide administration(2.1 : 25.7 and 2.2 : 27.4 mL/min/100 mL GFR), but not increased after hydrochlorothiazide treatment(2.1 : 1.6 and 2.2 : 2.6 mL/min/100 mL GFR). And the distal fractional chloride reabsorption was significantly decreased by furosemide injection (73% : 15% and 75% : 4.6%), whereas hydrochlorothiazide had no effect on it(73% : 63% and 75% : 78%). These findings indicate that our patients have a defect in thiazide-sensitive Na-Cl cotransporter in the distal tubule, which is compatible with the pathophysiology of Gitelman's syndrome.

• Journal of Microbiology and Biotechnology
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• v.29 no.11
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• pp.1693-1706
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• 2019

Atopic dermatitis (AD) is a chronic inflammatory skin disease of mainly infants and children. Currently, the development of safe and effective treatments for AD is urgently required. The present study was conducted to investigate the immunomodulatory effects of yeast-extracted β-1,3/1,6-glucan and/or Lactobacillus plantarum (L. plantarum) LM1004 against AD-like symptoms. To purpose, β-1,3/1,6-glucan and/or L. plantarum LM1004 were orally administered to AD-induced animal models of rat (histamine-induced vasodilation) and mouse (pruritus and contact dermatitis) exhibiting different symptoms of AD. We then investigated the treatment effects on AD-like symptoms, gene expression of immune-related factors, and gut microbiomes. Oral administration of β-1,3/1,6-glucan (0.01 g/kg initial body weight) and/or 2 × 10¹² cells/g L. plantarum LM1004 (0.01 g/kg initial body weight) to AD-induced animal models showed significantly reduced vasodilation in the rat model, and pruritus, edema, and serum histamine in the mouse models (p < 0.05). Interestingly, β-1,3/1,6-glucan and/or L. plantarum LM1004 significantly decreased the mRNA levels of Th2 and Th17 cell transcription factors, while the transcription factors of Th1 and Treg cells, galactin-9, filaggrin increased, which are indicative of enhanced immunomodulation (p < 0.05). Moreover, in rats with no AD induction, the same treatments significantly increased the relative abundance of phylum Bacteroidetes and the genus Bacteroides. Furthermore, bacterial taxa associated with butyrate production such as, Lachnospiraceae and Ruminococcaceae at family, and Roseburia at genus level were increased in the treated groups. These findings suggest that the dietary supplementation of β-1,3/1,6-glucan and/or L. plantarum LM1004 has a great potential for treatment of AD as well as obesity in humans through mechanisms that might involve modulation of host immune systems and gut microbiota.