• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.815-818
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• 2001

Indicator organisms are frequently used to monitor bacterial contamination of water. The most common indicator organisms used in water quality monitoring are coliforms and Escherichia coli. To develop a rapid and quantitative method for detecting the coliforms and E. coli in water, cell growth kinetics and defined substrate technology were applied in this study.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.207-209
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• 2005

Serum is a potential source of bacterial, mycoplasmal and viral contamination, and it has a possibility of the introduction of serum proteins, prion and pyrogens into the final vaccine product. For porcine Rotavirus vaccine production, it is necessary to develop serum free medium which do not cause those problems. A new serum free medium was developed for porcine Rotavirus vaccine based on DMEM, and the performance of developed serum free medium was evaluated in terms of Vero cell growth and Rotavirus vaccine production. The cell density, gown in serum free medium developed, was similar with that in serum supplemented medium. Also, it was higher than that in other commercially available serum free medium. The productivity of Rotavirus vaccine using serum free medium developed and optimum production strategies will be also discussed.

• Journal of Food Hygiene and Safety
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• v.10 no.1
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• pp.45-51
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• 1995

Ozone treatment was applied to ginseng powder for the improving hygienic quality of ginseng powder. A bacterial strain was isolated form ginseng powder contaminated. The strain designated as GT4, was identified as Escherichia coli species by IMVIC test method. Ozone inhibited strongly total bacteria and coliforms in ginseng powder(initial concentration 103/g) at 0.35 ppm. High ozone concentration reduced death time of the total bacteria in ginseng powder. However, ozone treatment caused significant degradation in saponins of ginseng powder. Ozone treatment also caused a increase in Hunter's color L value and decrease in a and b values of ginseng powder.

• Journal of Environmental Science International
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• v.11 no.6
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• pp.561-567
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• 2002

This study was investigated to evaluate the effect of the sodium ion and pH on toxicity of dinitrophenol at high concentrations (0.41 to 0.54 mM), over a sodium concentration range of 0.1 mM to 107 mM and over a pH range of 5 to 9. The concentration of sodium ions in the activated sludge mixed liquor seemed to have very little effect on dinitrophenol toxicity. However, lack of sodium in the growth media resulted in a reduction of the dinitrophenol degradation rate by bacterial isolate from the activated sludge culture, which has been identified as Nocardia asteroides. Dinitrophenol inhibition was found to be strongly dependent on mixed liquor pH. The dinitrophenol degradation rate was highest in the pH range of 6.95 to 7.84; at pH 5.94 degradation of 75 mg/L dinitrophenol was significantly inhibited; at pH < 5.77, dinitrophenol degradation was completely inhibited after approximately 30% of the dinitrophenol was degraded.

• Journal of Environmental Health Sciences
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• v.2 no.1
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• pp.17-19
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• 1975

Widal Test has been performed on the patients of 1052 admitted with suspicious typhoid for 5 years (Jan. '68 Dec. '72) White blood cell count, Hematocrit and Bacterial cultures are compared with widal titer and found a slight atypical variation from the characteristic pattern of it. 1. There is frequency distribution on the age of 20-40 yrs. as far as social activity concerned. (Table 1) 2. A slight leukopenia exists on the high titer of it but no definite pattern has been found. 3. S. Typhi has been grown on the low titer of it but no growth on the high titer. 4. It ia the most important in public health view point (no definite clinical symptom, Hematological, Serological, Microbiological characteristics.)

• Culinary science and hospitality research
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• v.8 no.3
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• pp.249-257
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• 2002

Gamma irradiation(1~10 kGy) was applied to chicken for the evaluation of their microbiological safety. In 3kGy-irradiated sample, the initial level of microbial contamination in chicken was 1.8$\times$10$^4$CFU/g (Coliforms), 2.2$\times$10$^3$CFU/g(Salmonella) and 2.7$\times$10$^3$CFU/g(Listeria), All kinds of contaminated microorganism were sterilized by 7kGy-irradiation. Also, irradiation followed by freeze storage at the same time was very effective in inhibiting bacterial growth. The pH was slightly increased during storage period and titratable acidity decreased. However, no significant changes in pH and acidity were observed by gamma irradiation.

• Food Science and Biotechnology
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• v.16 no.3
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• pp.398-403
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• 2007

The effectiveness of phage biocontrol depends on the activity of bacteriophage in a given environment. In order to investigate the infectivity and the stability of bacteriophages in representative environments, three virulent phages, Listeria phage A511, Salmonella phage Felix O1, and Escherichia coli phage T7, were subjected to different temperatures, pHs and salt concentrations (NaCl). Phage infectivity was also determined in the presence of divalent cations ($Mg^{2+}$ or $Ca^{2+}$). As a result, three phages exhibited a wide range of survival rates under various environments. Phage infectivity was directly correlated with bacterial growth under the applied conditions. One exception was Felix O1 that did not kill Salmonella grown in low pH (4.5). The failure was attributed to defective adsorption of Felix O1. This finding is significant as it provides an explanation for the inefficient phage biocontrol. Therefore, such information is crucial to improve phage biocontrol of pathogens.

• Journal of Microbiology and Biotechnology
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• v.5 no.3
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• pp.167-171
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• 1995

A bacterial strain C-02 using methanol as a carbon source was isolated from Gumi Industrial Estate and selected based on its rapid growth and capability of poly-$\beta$-hydroxybutyrate accumulation. Characteristics of strain C-02 showed that it belongs to the Methylococcaceae family, Type II subgroup. Strain C-02 could incorporate valerate into the PHB chain to form 3-hydroxybutyrate and 3-hydroxyvalerate (P(3HB-co-3HV)). Among various nutrient limitation tests, the nitrogen limitation test resulted in the highest content of P(3HB-co-3HV) per dry cell weight, 50$%$. Under the nitrogen limited condition, the average molecular weight of P(3HB-co-3HV) obtained was determined to be approximately $2.8\times 10^5$ daltons.

• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.393-398
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• 1996

In order to develop a lactic acid bacterial powder which can be used as a probiotic for human and animal, a lactic acid bacteria which has high resistance against low pH and ox-gall, and shows a good growth inhibition against E. coli, was isolated from an animal intestine and characterized. The isolated strain was identified as Enterococcus faecium. It had more than 90% of survival at low pH for 2 hours and almost 100% of survival in the presence of 0.3% ox-gall. When co-cultured with E. coli in MRS broth, all of the E. coli cells were killed within 24 hours. The final powdered product of the isolated strain was manufactured after a freeze drying process using an industrial media, and then checked its stability. Its storage stability was 80% for 11 months at 18$\circ$C.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.1
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• pp.78-84
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• 1996

The presence of ammonia, usually in the form of ammonium ion ($NH_4{^+}$), can enhance bacterial growth m the distribution system and make the production of drinking water more costly if ammonium must be removed to ensure good disinfection. Removal of ammonia by biological oxidation could be economical which prevents excess chlorine dosage In this research, effects of hydraulic retention time (HRT) and media type on the ammonia removal efficiencies of submerged biofilm reactor were investigated. The biofilm reactors combined the characteristics of high biological solids capture efficiency and good hydraulic control. The results indicate that biofilms can remove over 77 percent of the ammonia with HRT of longer than 2 hr even at low temperature ranging from 14.6 to $16.6^{\circ}C$. The HRT has a significant effect on nitrification. The overall nitrification and efficiency of ammonia removal increase with increasing HRT. It has also been observed that when the fibrous media was used, the ammonia removal, nitrification rate and endurance to shock improved.