• Food Science of Animal Resources
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• v.18 no.1
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• pp.63-74
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• 1998

Recently the high outbreaks of intestinal disease caused by the consumption of frozen dairy foods containing pathogenic bacteria has generated considerable interest in the causative agent such as Listeria monocytogenes and E. coli O157:H7. This study was carried out to detect the above pathogens and compare the microbiological qualities of three commercial forzen yogurt products. The main results obtained were as follows. L. monocytogenes coliforms and E. coli O157:H7 were not detected in the total of seven frozen yogurt samples. For microbiological qualities the viable lactic counts of products manufactured by FA company were about 2.9$\times$108 -1.6$\times$109cfu/ml 1.7$\times$106 cfu/ml for FB's and 1.2$\times$106 cfu/ml for FC's The PH values of FA's FB's and FC's products was in the range of pH 4.1~5.3 and the values of FA's were 4.1~4.6 compared by the pH 5.2~5.3 of FB's and FC's products. During refrigeration of the test samples the survival rates of L. monocytogenes spiked into thawed frozen yogurt sample(FA's FB,s and FC's) were 0.55% 15.61% and 16.89% respectively. On the other hand E. coli O157:H7 and L. monocytogenes were 12.4% and 25.0% for FA's 10.8% and 20.8% for FB's and 10.26% and 22.7% for FC's under 37$^{\circ}C$ storage, As the results described above each frozen yogurt products were different in microbiological qualities. The survival rates of pathogens spiked into the samples increased with the pH of the products. This indicates that the pH or any other factors pre-sumable supressed the growth of E. coli O157:H7 and L. monocytogenes in frozen yogurt products.

• Journal of The Korean Dental Society of Anesthesiology
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• v.14 no.1
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• pp.49-56
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• 2014

Background: Propofol (2.6-diisopropylphenol) is a widely used intravenous anesthetic agent for the induction and maintenance of anesthesia during surgeries and sedation for ICU patients. Propofol has a structural similarity to the endogenous antioxidant vitamin E and exhibits antioxidant activities.13) However, the mechanism of propofol on hypoxia/reoxygenation (H/R) injury has yet to be fully elucidated. We investigated how P-PostC influences the autophagy and cell death, a cellular damage occurring during the H/R injury. Methods: The groups were randomly divided into the following groups: Control: cells were incubated in normoxia (5% CO2, 21% O2, and 74% N2) without propofol treatment. H/R: cells were exposed to 24 h of hypoxia (5% CO2, 1% O2, and 94% N2) followed by 12 h of reoxygenation (5% CO2, 21% O2, and 74% N2). H/R + P-PostC: cells post-treated with propofol were exposed to 24 h of hypoxia followed by 12 h of reoxygenation. 3-MA + P-PostC: cells pretreated with 3-MA and post-treated propofol were exposed to 24 h of hypoxia followed by 12 h of reoxygenation Results: The results of our present study provides a new direction of research on mechanisms of propofol-mediated cytoprotection. There are three principal findings of these studies. First, the application of P-PostC at the onset of reoxygenation after hypoxia significantly increased COS-7 cell viability. Second, the cellular protective effect of P-PostC in H/R induced COS-7 cells was probably related to activation of intra-cellular autophagy. And third, the autophagy pathway inhibitor 3-MA blocked the protective effect of P-PostC on cell viability, suggesting a key role of autophagy in cellular protective effect of P-PostC. Conclusions: These data provided evidence that P-PostC reduced cell death in H/R model of COS-7 cells, which was in agreement with the protection by P-PostC demonstrated in isolated COS-7 cells exposed to H/R injury. Although the this study could not represent the protection by P-PostC in vivo, the data demonstrate another model in which endogenous mechanisms evoked by P-PostC protected the COS-7 cells exposed to H/R injury from cell death.

• KSBB Journal
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• v.16 no.5
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• pp.523-525
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• 2001

Curdlan is one biopolymer composed of ${\beta}$1,3-glucan and dissolved in a alkali solution but formed salt under neutral or acid condition. It was produced by Agrobactrium species and the separation process is necessary to make pure curdlan from the culture broth. The pH swing separation method was as feasible separation process using solubility changes with the pH difference. however, this method requires a lot of acid and alkali solution also produces a lot of waste. Therefore, an efficient process which could save energy and minimize toxic waste was developed. A density gradient separation process was developed in this research. High density sucrose solution was used as a separation agent. Curdlan was separated from the culture broth when the density of the sucrose solution was 1.15 g/L. Since the curdlan was produced on the surface of cell wall. the pre-treatment of culture broth was necessary. Curdlan recovery yield was increased up to 83% with the homogenization of the culture broth and further increased up to 87% with the treatment of alkai-acid solution.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.167-170
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• 2004

A self-directing optimization procedure was applied to determine the best environmental factors in operating the bioreactor. The self-directing optimization process was employed to determine the best conditional combination of multi parameters, pH, temperature, aeration rate and mixing rate toy maximal production of chitinase by Trichoderma harzianum SJG-99721 in batch mode fermentation. Among these factors, the parameters of pH and aeration rate were found to be particularly important on mycellial growth and chitinase activity. pH 4.89, an aeration rate of 3.22 ι per minute and an agitation rate of 225 rpm was found to be the best combination. By the optimization, chitinase activity was dramatically increased from an initial value of 4.221 U under basic conditions to n final value of 16.825 U.

• Journal of the Korean Wood Science and Technology
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• v.34 no.1
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• pp.40-51
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• 2006

The objective of this research is to analyze a possibility for the utilization of carbonized bark and develop the technique for carbonization of bark for using as the adsorbent, the soil improvement agent, the carrier for microbial activity, health products, and so on. The properties of bark charcoals such as methylenehlue adsorption (MBA), equilibrium moisture content (EMC), far infra rad emissivity, pH, water retention and caloric value were analyzed. The MBA values of bark charcoals carbonized for 8 hr of carbonization time at $800^{\circ}C$ of carbonization temperature for Larix leptolepis, Pinus koraiensis, Pinus rigida were greater than 110 mg/g. The bark charcoals pH values of all three species that were carbonized for 4 hr of carbonization time at $400^{\circ}C$ of carbonization temperature was 6.6 and carbonized for 4 hr at 600 and $800^{\circ}C$ was about 9. Therefore the bark charcoals of those species could be used as charcoals if the carbonization temperature and time were controlled.

• Korean Journal of Plant Resources
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• v.12 no.4
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• pp.289-296
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• 1999

The availability of Bacillus polimyxa 'HB 26-5' as a biological control agent was investigated. The antagonistic bacteria Bacillus polymyxa 'HB 26-5' grew well on the media at pH 7.0 and the optimum growth temperature was $25^{\circ}C$. The pH of the media changed to weak acid(pH 6.1~6.5) at the beginning of incubation, but to weak alkali(pH 7.8~8.2) at 7days after incubation. The best carrier to enhance colonization of the bacteria were the mixture of rice bran and peat, or rice bran and kaoline, in those formulation the density of the bacteria was changed slightly, though the density was beginning to decrease 3 weeks after application at field. In view of the physical characteristics of the formulation for the density maintenance during storage such as the hardness and the size, the best one was the formulation consisted of sodium alginate 2%, kaolin 15% and rice bran 3%.

• Korean Journal of Plant Resources
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• v.23 no.5
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• pp.430-435
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• 2010

This study was performed to investigate the antimicrobial effects of Ampelopsis brevipedunculata ethanol-extract on food spoilage or foodborne disease microorganism. The antimicrobial activity of Ampelopsis brevipedunculata extract was determined by a paper disc method. The extract exhibited growth inhibiting activities in a concentration dependent manner on 7 species of microorganisms. The extract of Ampelopsis brevipedunculata showed the highest antimicrobial activity against Escherichia coli O157:H7. The growth inhibitory effects of the extract at the concentration of 250, 500, 1,000, 2,000 mg/L on food poisoning microorganism were determined against Salmonella typhimurium, Yersinia enterocolitica, Escherichia coli O157:H7 and Staphylococcus aureus. The growth of microorganisms was not affected by the extract at the concentration up to 250 mg/L, but was significantly (p<0.05) inhibited by the extract at the concentration higher than 500 mg/L. The results in the present study demonstrate antimicrobial effects of Ampelopsis brevipedunculata ethanol-extract against foodborne pathogens, suggesting that Ampelopsis brevipedunculata could be an effective natural antibacterial agent in food.

• Journal of the Korean Ceramic Society
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• v.52 no.4
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• pp.264-268
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• 2015

Cu films were plated in an eco-friendly electroless bath (No-Formaldehyde) on Ni/screen printed Ag pattern/PET substrate. For electroless Cu plating, we used sodium-phosphinate ($NaH_2PO_2{\cdot}H_2O$) as reducing agent instead of Formaldehyde. All processes were carried out in electroless solution of pH 7 to minimize damage to the PET substrate. According to the increase of sodium-phosphinate, the deposition rate, the granule size, and rms roughness of the electroless Cu film increased and the Ni content also increased. The electroless Cu films plated using 0.280 M and 0.575 M solutions of sodium-phosphinate were made with Cu of 94 at.% and 82 at.%, respectively, with Ni and a small amount P. All electroless Cu plated films had typical FCC crystal structures, although the amount of co-deposited Ni changed according to the variation of the sodium-phosphinate contents. From these results, we concluded that a formation of higher purity Cu film without surface damage to the PET is possible by use of sodium-phosphinate at pH 7.

• Korean Journal of Materials Research
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• v.24 no.11
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• pp.632-638
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• 2014

We investigated the effects of DMAB (Borane dimethylamine complex, C2H10BN) in electroless Ni-B film with addition of DMAB as reducing agent for electroless Ni plating. The electroless Ni-B films were formed by electroless plating of near neutral pH (pH 6.5 and pH 7) at $50^{\circ}C$. The electroless plated Ni-B films were coated on screen printed Ag pattern/PET (polyethylene terephthalate). According to the increase of DMAB (from 0 to 1 mole), the deposition rate and the grain size of electroless Ni-B film increased and the boron (B) content also increased. In crystallinity of electroless Ni-B films, an amorphization reaction was enhanced in the formation of Ni-B film with an increasing content of DMAB; the Ni-B film with < 1 B at.% had a weak fcc structure with a nano crystalline size, and the Ni-B films with > 5 B at.% had an amorphous structure. In addition, the Ni-B film was selectively grown on the printed Ag paste layer without damage to the PET surface. From this result, we concluded that formation of electroless Ni-B film is possible by a neutral process (~green process) at a low temperature of $50^{\circ}C$.

• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.407-411
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• 1989

Extracellular neutral pretense of Streptomyces rimosus producing oxytetracycline was purified by ammonium sulfate fractionation, DEAE Sephadex A-50 chromatography and Sephadex G-100 gel filteration, and was showed single band on the cathodic gel electrophoresis. The optimum pH and temperature of the enzyme were pH 8.0 and 6$0^{\circ}C$, respectively. The enzyme was activated about 80% in the presence of Co$^{2+}$ ion, and strongly inhibited by Hg$^{2+}$, Fe$^{2+}$ and chelatig agent, EDTA. Molecular weight of the enzyme was estimated to be 12, 000. The Km value of the enzyme of casein as a substrate was 2.7$\times$10$^{-4}$M.