• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.9
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• pp.1106-1112
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• 2007

The solvent extracts of Euphorbia helioscopia, which were extracted by using several solvents with different polarities, were prepared for utility as natural preservatives. The E. helioscopia extract by 80% ethanol was sequentially fractionated with n-hexane, dichloromethane, ethylacetate, and butanol. In order to effectively screen for a natural preservatives agent, we first investigated the antioxidant activities such as DPPH radical scavenging capacity, superoxide radical scavenging capacity, and xanthine oxidase inhibitory activity of the E. helioscopia extracts. By the screening system, we found that ethylacetate fraction had the strongest antioxidant activity in a dose-dependent manner. The antimicrobial activities and cell growth inhibition were investigated for each strain with the different concentrations of E. helioscopia extracts. Antimicrobial activities were shown in ethylacetate fraction of E. helioscopia; however, ethanol, butanol and water fractions showed weak antimicrobial activity against the tested microorganisms. Among the five fractions, ethylacetate fraction showed the highest antimicrobial activities against microorganisms tested, such as Bacillus sublitis, Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella Enteritidis and Salmonella Typhimurium. The polyphenol content from ethanol, n-hexane, dichloromethane, ethylacetate, butanol, and water fractions were 207.46 mg/g, 45.45 mg/g, 138.23 mg/g, 678.02 mg/g, 278.91 mg/g, and 63.76 mg/g, respectively. There seems to be a close relationship between antioxidant activities, and antimicrobial activities and polyphenol content in natural plant. From these results, it is suggested that E. helioscopia could be used for the ethylacetate fraction and could be suitable for the development of a food preservative.

• Journal of dental hygiene science
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• v.9 no.2
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• pp.249-255
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• 2009

This study was carried out for the purpose of comparing bacterial culture method, single PCR, and multiplex PCR for identification of F. nucleatum and A. actinomycetemcomitans in subgingival plaque of adult periodontitis. Targeting 20 patients with adult periodontitis, the subgingival plaque was collected in teeth, respectively, for #16, #36, #44. A bacillus was cultivated by painting it over the solid selective media of F. nucleatum and A. actinomycetemcomitans. Bacterial species were detected in 0 tooth with 12 pieces, respectively. Through single PCR and multiplex PCR, the positive reaction was indicated in 43 teeth with 45 pieces, respectively, as for F. nucleatum, and in 1 tooth with 4 pieces, respectively, as for A. actinomycetemcomitans. In the comparative analysis between bacterial identification methods. F. nucleatum showed the more statistically significant difference(p=0.0(0) in comparison between single PCR and multiplex PCR. Even A. actinomycetemcomitans was indicated significantly(p=0.067) in a case that is based on 0.1 in significant level in the comparison between single PCR and multiplex PCR. In conclusion, as a result of comparing the bacterial identification methods, the detection frequency was indicated to be higher in PCR than in bacterial culture method. Single PCR and multiplex PCR showed the mutually similar detection frequency. Accordingly, given thinking of economic efficiency, quickness, and reduction in labor force, it is thought to be more efficient method to use single PCR as the bacterial identification method.

• Journal of Radiation Industry
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• v.5 no.1
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• pp.75-80
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• 2011

This study was to determine the microbiological safety and tensile strength of gammairradiated porcine tendon for the development of safe xenografts. Escherichia coli and Bacillus subtilis were used as model pathogens and inoculated as $10^6{\sim}10^7log$ colonies forming unit $(CFU)g^{-1}$. As model virus from porcine, porcine parvovirus (PPV), bovine viral diarrhoea virus (BVDV) and poliovirus were inoculated as $10^5{\sim}10^6$ tissue culture infectious dose $(TCID)_{50}g^{-1}$ into porcine skin. The $D_{10}$ value of E. coli and B. subtilis was measured as $0.32{\pm}0.082kGy$ and $4.0{\pm}0.312kGy$, respectively. Additionally, the $D_{10}$ values of PPV, BVDV and poliovirus were also shown as $1.75{\pm}0.131kGy$, $3.70{\pm}0.212kGy$ and $6.26{\pm}0.332kGy$, respectively. Gamma irradiation decreased the tensile strength of porcine tendon. Results indicate that microbiological safety of porcine tendon can be improved significantly by gamma irradiation. However, further studies are needed to improve the tensile strength of gamma-irradiated porcine tendon.

• Journal of Radiation Industry
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• v.7 no.1
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• pp.29-35
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• 2013

Microbiological populations and the sterility of commercial powdered products treated with gamma irradiation at 0~10 kGy were investigated before using them as ingredients for a non-cooked Saengsik product. We evaluated a total of 14 powdered products: 8 powdered cereals, 3 powdered tubers, and 3 powdered leafy vegetables. The total numbers of bacterial populations in non-irradiated powdered cereals, tubers, and leafy vegetables were 2.7~6.9, 5.6~6.0, and $5.3{\sim}6.8\;log\; CFU{\cdot}g^{-1}$, respectively. Moreover, coliform bacteria were not indicated in adlay, millet, germinated brown rice, soybean, and mulberry leaves powder within detection limit ($2.0\;log\; CFU{\cdot}g^{-1}$). The number of Bacillus cereus exceeded $3.0\;log\; CFU{\cdot}g^{-1}$ (the maximum limit for Saengsik products) in all samples, excluding perilla seeds, buckwheat, barley, oat, potato, and Jerusalem artichoke powder. However, a dose of 6 kGy of gamma irradiation reduced the microbiological populations in all samples, and all the powdered products met the microbial requirements for Saengsik products. Futhermore, it was confirmed that all microorganisms in the 9 powdered products, except fermented brown rice, sweet potatoes, and 3 leafy vegetables, were sterilized by 10 kGy of gamma irradiation.

• Food Science and Preservation
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• v.12 no.4
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• pp.323-328
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• 2005

This study were investigated to analyzed an optimum preparation condition of coating film and its antimicrobial activity on pathogenic and deteriorative bacteria to obtain fundamental data for development of active packaging film using antimicrobial peptide, polysine. In the preparation conditions of coating film, antimicrobial activity was depending on the concentration of polylysine and polyamide respectively, and relatively high activity was obtained in the film prepared with more than $1.0\%$ (w/v) of polylysine, $40\%$ (w/v) polyamide, and more than $50\;{\mu}m$ of film thickness. Concentration of polylysine migrated from coated film to distilled water was reached at the maximum concentration, about 20 ppm after 3 days and in equilibrium after 7 days of soaking in sterilized water. An antimicrobial activity of coated film showed bactericidal effect of about $10^5\;CFU/mL$ comparing with the control against Bacillus cereus having $4.8{\times}10^5\;CFU/mL$ of initial viable cell numbers, and of about $10^2\;CFU/mL$ comparing with the control against Klebsiella pneumoniae having $6.8{\times}10^5\;CFU/mL$ of initial viable cell numbers. Consequently, it was revealed that polylysine coating film has a potential of applicable possibility as antimicrobial packaging film.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.469-476
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• 2015

Button mushroom compost (BMC) was prepared by fermenting the mixture of waste button mushroom bed collected from Boryeong area in South Korea (4): sawdust (8) : pig and fowl manure (1) for 40 days at $30^{\circ}C$. The BMC compromised diverse microorganisms including aerobic bacteria $8.1{\times}10^6cfu\;g^{-1}$, Gram negative bacteria $1.7{\times}10^7cfu\;g^{-1}$, genus Bacillus $6.4{\times}10^6cfu\;g^{-1}$, genus Pseudomonas $1.5{\times}10^4cfu\;g^{-1}$, actinomycetes $1.0{\times}10^4cfu\;g^{-1}$, and fungi $3.5{\times}10^3cfu\;g^{-1}$. BMC was used as a microbial inoculant for estimating the mobilization of heavy metals in soil or plant. When metal solubilization potential of BMC was assessed in a batch experiment, the inoculation of BMC was shown to increase the concentrations of water soluble Co, Pb, Cd, and Zn by 29, 26, 27, and 43% respectively, than those of non-inoculated soils. BMC-assisted growth promotion and metal uptake in sunflower (Helianthus annuus) was also evaluated in a pot experiment. In comparison with non-inoculated seedlings, the inoculation led to increase the growth of H. annuus by 17, 15, 18, and 21% respectively in Co, Pb, Cd, and Zn contaminated soils. Moreover, enhanced accumulation of Co, Pb, Cd, and Zn in the shoot and root systems was observed in inoculated plants, where metal translocation from root to the above-ground tissues was also found to be enhanced by the BMC. The apparent results suggested that the BMC could effectively be employed in enhancing phytoextraction from the soils contaminated with heavy metals such as Co, Pb, Cd, and Zn.

• Food Engineering Progress
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• v.15 no.4
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• pp.370-375
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• 2011

In this study the polymerase chain reaction (PCR) combined with denaturing gradient gel electrophoresis (DGGE) was evaluated as a method permitting the rapid detection of pathogens in fresh originally grown vegetables. A universal primer (341GCf/534r) was selected for its ability to amplify the V3 region of 16S-rRNA genes in their target pathogens (Salmonella typhimurium, Pseudomonas fluorescens, Bacillus cereus, Listeria monoytogenes, Staphyloocus aureus, E. coli). The 194 bp fragments in PCR were successfully duplicated as expected. The amplified fragments of the same size from six different pathogens also showed good separation upon DGGE. The detection limit of PCR-DGGE for six pathogens in fresh-cut lettuces were over $10^{5}$ CFU/g when sampled by stomaching. However, when the sampling method was changed from stomaching to shaking, the detection limit of six pathogens in organic vegetables was shown to increase by over $10^{1}$ CFU/g, but only those of B. cereus were over $10^{3}$ CFU/g. Therefore, PCR-DGGE was shown to be a reliable method for the detection of pathogens in fresh-cut vegetables.

• Journal of Ginseng Research
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• v.43 no.1
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• pp.116-124
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• 2019

Background: Ginsenosides are known as the principal pharmacological active constituents in Panax medicinal plants such as Asian ginseng, American ginseng, and Notoginseng. Some ginsenosides, especially the 20(R) isomers, are found in trace amounts in natural sources and are difficult to chemically synthesize. The present study provides an approach to produce such trace ginsenosides applying biotransformation through Escherichia coli modified with relevant genes. Methods: Seven uridine diphosphate glycosyltransferase (UGT) genes originating from Panax notoginseng, Medicago sativa, and Bacillus subtilis were synthesized or cloned and constructed into pETM6, an ePathBrick vector, which were then introduced into E. coli BL21star (DE3) separately. 20(R)-Protopanaxadiol (PPD), 20(R)-protopanaxatriol (PPT), and 20(R)-type ginsenosides were used as substrates for biotransformation with recombinant E. coli modified with those UGT genes. Results: E. coli engineered with $GT95^{syn}$ selectively transfers a glucose moiety to the C20 hydroxyl of 20(R)-PPD and 20(R)-PPT to produce 20(R)-CK and 20(R)-F1, respectively. GTK1- and GTC1-modified E. coli glycosylated the C3-OH of 20(R)-PPD to form 20(R)-Rh2. Moreover, E. coli containing $p2GT95^{syn}K1$, a recreated two-step glycosylation pathway via the ePathBrich, implemented the successive glycosylation at C20-OH and C3-OH of 20(R)-PPD and yielded 20(R)-F2 in the biotransformation broth. Conclusion: This study demonstrates that rare 20(R)-ginsenosides can be produced through E. coli engineered with UTG genes.

• Journal of Mushroom
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• v.16 no.4
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• pp.257-262
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• 2018

The aim of this study was to re-use spent mushroom substrate (SMS) with increased total nitrogen (T-N) and amino acid content and reduce the amount of cottonseed meal used as nutrient supplement in Pleurotus ostreatus cultivation. Bacteria used for improvement of the T-N content were GM20-4(Bacillus sp.) and Rhodobacter sphaeroides (RS). GM20-4 was isolated from the SMS of P. ostreatus and RS was obtained from Gwangjusi agricultural technology center. SMS in T1, T2, and T3 was reused as substrate after drying and the T-N content of dried SMS (D-SMS) was increased by 0.34% by treatment with the bacteria. T1 with 8% D-SMS and T2 with 18% D-SMS had higher rates of primordia formation compared with T3 and the control. The biological efficiency of the control and of treatment with 8%, 18%, and 26% D-SMS was 110%, 114%, 112%, and 79%, respectively. Considering the economic cost, yield, and biological efficiency, T2 with 18% D-SMS as the culture substrate for P. ostreatus was shown to be the most effective for cultivation.

• Food Engineering Progress
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• v.21 no.1
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• pp.88-92
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• 2017

We attempted to investigate antibacterial and proteolytic activities of bacteria isolated from three ethnic fermented seafoods in the east coast of South Korea, gajami sikhae, squid jeotgal, and fermented jinuari (Grateloupia filicina). Bacillus cereus ATCC 14579, Listeria monocytogenes ATCC 15313, Staphylococcus aureus KCTC 1916, Escherichia coli O157:H7 ATCC 43895, and Salmonella enterica serovar Typhimurium ATCC 4931 were selected to determine the antibacterial activity of the bacterial isolates. Among 233 isolates from the three foods, 36 isolates (15.5%) showed antibacterial activity against B. cereus ATCC 14579, the highest incidence of inhibition, followed by S. aureus KCTC 1916 (7.7%) and L. monocytogenes ATCC 15313 (6.0%). However, only five and three strains among the isolates exhibited inhibitory activity against Gram-negative indicators, E. coli ATCC 43895 and Sal. enterica ATCC 4931, respectively. The proteolytic activity of the isolates was determined via hydrolysis of skim milk after 24, 48, and 72 h incubation. After 72 h incubation, 72 out of 233 isolates (30.9%) showed proteolytic activity, and the isolates of fermented jinuari exhibited the highest incidence of proteolytic activity (60%, 36 isolates). These results suggest that ethnic fermented seafoods in the east coast of South Korea might be a promising source of bacterial strains producing antibacterial and proteolytic compounds.