• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.377-382
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• 2003

Purification of methioninase resulted in a yield of 69%, and SDS-PAGE analysis of the purified product revealed a single band of approximately 43 kDa in molecular weight. in vitro experiments with cancer cells incubated in methionine-free media demonstrated an increase in $^{11}$ C-methionine uptake to 25.8$\pm$1.1% at 6 hr, 31.8$\pm$0.8% at 24 hr, and 62.2$\pm$0.6% at 48hr, compared to controls. Treatment of the cancer cells with purified methioninase showed no decrease in survival after a 2 hr incubation with 0.01 U/ml, but survival of RR1022 cells decreased 30% after 24 to 48 hr incubation. SKOV-3 cells showed a 5% and 14% decrease in survival with 0.1 and 1 U/ml methioninase after 24 hr. After 48hr survival decreased 15% and 24% with 0.1 and 1 U/ml methioninase. Measurements of $^{11}$ C-methionine uptake in RR1022 cells demonstrated no change at 2 hr, but a 13.7$\pm$4.7% and 40.7$\pm$2.6% increase in uptake at 24 and 48 hr, respectively. SKOV-3 cells also showed no change at 2 hr, but had a 17.7$\pm$7.2% and 38.9$\pm$4.9% increase in $^{11}$ C-methionine uptake after 24 hr and 48 hr treatment with methioninase, respectively. $^{11}$ C-methionine PET imaging revealed clear visualization of both the tumors and contralateral infectious lesions. Administration of rMET appeared to result in a slight increase in tumor:nontumor contrast on $^{11}$ C-methionine PET images. Injection of purified methioninase also produced PET images where tumor uptake was higher than that of infectious lesions.

• Korean Journal of Microbiology
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• v.32 no.2
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• pp.147-154
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• 1994

Nuclease was secreted to the environmental media from the Escherichia coli JM107 tranformant harboring the extracellular nuclease gene of Serratia marcescens in the plasmid of pNUC4. Under the growth conditions, the amount of secreted enzyme was increased in parallel with bacterial growth conditions, the amount of secreted enzyme was increased in parallel with bacterial growth. The enzyme was purified using chromatofraphic procedures of Matrex green gel and heparin agarose affinity gel, resulted in 50-fold purification with 15% recovery of the enzyme. The apparent molecular weight of the enzyme was estimated to be 29Kda by sodium dodecylsulfate denaturing gel electrophoresis. Using the purified enzyme, polyclonal antibody was obtained from the rabbit. The specificity of the antibody was confirmed by immunoblotting and immunoprecipitaion. For the investigation of cellular distribution of the enzyme, cells were fractionated into three fractions; cytoplasm, periplasm and extracellular fluid. While more than 80% of the enzymatic activity was detected in the extracellular fluid and periplasm, a little was found in the cytoplasm, indicating that the enzyme was likely to be immediately exported to the membrane for excretion after biosynthesis. These results were confirmed again by immunocytochemistry technique using the antibody.

• Journal of Life Science
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• v.26 no.2
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• pp.220-225
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• 2016

Coagulase-negative staphylococci (CNS) have recently become the bacteria most frequently found in clinical infections. The aim of this study was to investigate the prevalence, antimicrobial susceptibilities, and molecular characteristics of CNS isolates from dental clinic environments in Busan, Korea. One hundred and fifty-four samples were collected from 10 dental clinics and dental hospitals in Busan from December 2014 to January 2015. Species were identified by matrix-assisted laser desorption/ionization–time-of-flight. Antimicrobial susceptibility was determined by disk diffusion methods. A polymerase chain reaction was performed to detect mecA, mupA gene, and SCCmec types. Of the 154 samples, 10(6.5%) isolates were identified as CNS (5 Staphylococcus epidermidis, 2 Staphylococcus capitis, 2 Staphylococcus, and 1 Staphylococcus haemolyticus). Among the 10 isolates, 6 were resistant to penicillin, 5 were resistant to gentamicin, 3 were resistant to tetracycline, and 2 were resistant to cefoxitin and erythromycin. However, clindamycin, ciprofloxacin, teicoplanin, and trimethoprim-sulfamethoxazole resistant isolates were not present. Genes encoding mecA were detected in 4 (2 S. warneri and 2 S. haemolyticus) isolates, and mupA in 1 (S. epidermidis) isolate. One methicillin-resistant CNS (S. warneri) isolate was determined as being of the SCCmec type I. It is concluded that CNS resistant to various antimicrobial agents was widely distributed in dental clinic environments in Korea.

• Journal of Animal Environmental Science
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• v.2 no.1
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• pp.53-62
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• 1996

This experiment was conducted to investigate the effect of the reuse of sawdust fermented with swine excretion as bed material on the growth performance of pigs. The sawdust which was already fermented with swine excretion in the pig house for eight months was transported to a fermentation facility for secondary fermentation. A total of 96 pigs with average 30kg of initial body weight were randomly assigned in the $2{\times}2$ factorial design with two levels(0%, 1.5%) of probiotics added for secondary fermentation and two levels(0%, 1.5%) of probiotics in feed. The results obtained are as follows : 1. Total-nitrogen(T-N), $K_2O$, total-carbon(T-C), and carbon/nitrogen(C/N) in sawdust bed showed no significant difference within treatments, but phosphate increased by 57% in average compared to the initial. 2. There was no significant difference in temperature in the sawdust bed treatments. 3. The internal parasite eggs detected were Trichuris suis, Strong. ransomi, Ascaris suum, Coccidia and Balantidium coli. 4. The utilization period of sawdust fermented with swine excretion was 52, 26, 16, 4, 5, 3 days, respectively, with increase of body weight. 5. Average daily gain and feed conversion were significantly improved by adding probiotics in the feed(P<0.05), but there was no difference between fermented sawdust with or without probiotics. 6. There was no significant difference in carcass weight and backfat thickness of pig among treatments(P>0.05).

• Korean Journal of Food Science and Technology
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• v.40 no.2
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• pp.220-227
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• 2008

In this study, polysaccharides were isolated from Korean persimmon vinegar to characterize the polysaccharides existing as soluble forms within traditional Korean fermented beverages, and their immuno-stimulating activities were examined. Three successive chromatographies were used to purify the main polysaccharide in the persimmon vinegar, PV-1b-I, to homogeneity from the crude polysaccharide (PV-0). The molecular mass of PV-1b-I was estimated as 110 kDa and it contained significant proportions of mannose (46.8%), galactose (28.5%) and arabinose (19.1%). PV-1b-I strongly reacted with ${\beta}$-glucosyl Yariv reagent, suggesting the presence of an arabino-3,6-galactan moiety. PV-1b-I also induced high levels of macrophage activation and mitogenicity on murine splenocytes in vitro. The intravenous administration of PV-1b-I significantly augmented NK cytotoxicity against YAC-1 tumor cells. PV-1b-I also showed potent anticomplementary activity in a dose-dependent manner. Finally, C3 activation products were identified by crossed immunoelectrophoresis using anti-human C3 and the anti-complementary activity of PV-1b-I under $Ca^{2+}$-free conditions, suggesting that this PV-1b-I causes complementary activations via both alternative and classical pathways. From these results, one can conclude that Korean persimmon vinegar contains select polysaccharides in addition to healthy components, and these polysaccharides appear to provide immuno-stimulating activities beneficial to human health.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.737-750
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• 2015

This study was carried out to construct a DNA profile database for 102 watermelon cultivars through the comparison of polymorphism level and genetic relatedness using genomic microsatellite (gMS) and expressed sequence tag (EST)-microsatellite (eMS) markers. Sixteen gMS and 10 eMS primers showed hyper-variability and were able to represent the genetic variation within 102 watermelon cultivars. With gMS markers, an average of 3.63 alleles per marker were detected with a polymorphism information content (PIC) value of 0.479, whereas with eMS markers, the average number of alleles per marker was 2.50 and the PIC value was 0.425, indicating that eMS detects a lower polymorphism level compared to gMS. Cluster analysis and Jaccard's genetic distance coefficients using the unweighted pair group method with arithmetic average (UPGMA) based on the gMS, eMS, and combined data sets showed that 102 commercial watermelon cultivars could be categorized into 6 to 8 major groups corresponding to phenotypic traits. Moreover, this method was sufficient to identify 78 out of 102 cultivars. Correlation analysis with Mantel tests for those clusters using 3 data sets showed high correlation ($r{\geq}0.80$). Therefore, the microsatellite markers used in this study may serve as a useful tool for germplasm evaluation, genetic purity assessment, and fingerprinting of watermelon cultivars.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.1085-1093
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• 2017

Plasticizers are materials added to give softness and elasticity to plastics having rigid properties to give soft properties as products, and they are mainly added to high molecular materials to give flexibility to improve workability and to improve cold resistance, resistance to volatility and electrical properties. It is used for the purpose. Most plasticizers are inert liquids, similar in function to solvents but with high molecular weight and no volatility. In addition, when dissolved in petrochemical products, only the plasticizer is separated by the matrix effect with other compounds, and qualitative and quantitative analysis. In this study, qualitative and quantitative analysis of DOA and DOP, which are representative components of petrochemical products, were conducted using MD-GC/MS and developed an optimal plasticizer analysis method.

• Journal of agriculture & life science
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• v.43 no.1
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• pp.25-33
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• 2009

This study was carried out to isolate and characterize the glycomacropeptide (GMP) prepared from cow's milk and Korean native goat's milk and to examine the effects of their tryptic hydrolysates on inhibition of platelet aggregation in an in vitro experiment. The GMP derived from Holstein, Korean native goat and Hanwoo migrated at 20 KDa. Sialic acid contents in skim milk of Holstein, Korean native goat and Hanwoo were $36.86{\pm}2.36$, $37.98{\pm}1.27$ and $31.19{\pm}1.87{\mu}g/mg$, respectively. Tyrosine was detected in both bovine and caprine GMP. The in vitro inhibition rate of platelet agregation by tryptic hydrolysates of Holstein, Korean native goat and Hanwoo GMP were 4.02, 5.51 and 12.77%, respectively at reaction time 30 seconds. The inhibition of platelet aggregation by tryptic hydrolysates of bovine and caprine GMP are increased with increasing reaction time. The platelets staining revealed higher counts of platelets after the addition of GMP hydrolysates; however addition of ADP reduced the platelet count within 30 seconds and the platelets were not detected after 120 seconds. The results of this study indicate that tryptic hydrolysates of bovine and caprine GMP contain some small peptides with platelet aggregation inhibition properties. Further research on these lines may help prevent platelet aggregation related abnomalities in human.

• Journal of Sericultural and Entomological Science
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• v.50 no.2
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• pp.145-149
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• 2012

Cecropin is a well-studied antimicrobial peptide that play important role as key factor in insect humoral immunity. In this study, cecropin-like antimicrobial peptide was isolated and purified from the larval haemolymph of immune-challenged japanese oak silkworm, Antheraea yamamai. To isolate antimicrobial peptide, we separated and compared acidic extracted hemolymph protein bends between control and immune-challenged larvae using SDS-PAGE analysis. In the immune hemolymph extract, but not of non-immune hemolymph, we detected differential expressed peptide band with molecular mass 4,223.01 Da. To understand this peptide better, we successfully purified this peptide using cation exchange chromatography and gel permeation chromatography. Its N-terminal amino acid sequence obtained by Edman degradation evidenced a significant degree of identity with other lepidopteran cecropins. The purified A. yamamai cecropin-like peptide showed a broad spectrum of activity against fungi, Gram-negative and Gram-positive bacteria.

• Research in Plant Disease
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• v.26 no.4
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• pp.239-249
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• 2020

To find out the cause of the fire blight outbreak in apples and pears of Korea in 2019, we investigated disease appearing situation of thirty fire blight infected orchards, and interviewed farmers to determine the cultivation characteristics. Fire blight occurred mostly in orchards that had infected more than 2 years before. The cause of this were as follows: farmers did not know the symptoms of the disease properly. It is presumed that it has spread from the first occurrence to the surrounding orchards by flower-visiting insects or farmers and to a short distance or a long distance by the same cultivator or co-farmer. These series of processes repeated in the newly spreading area, and then disease reports increased as farmers became aware of fire blight. To minimize the spread of fire blight in Korea, it suggested that thorough education of farmers for early diagnosis and quantitative detection technology that can diagnose even in no symptom showing plants. And chemical or biological spraying systems suitable for domestic cultivation methods, which are producing large fruits, and molecular epidemiological studies of pathogens.