• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.2
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• pp.170-179
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• 2017

The purpose of this study was to compare the cariogenicity of commercially available bovine milk and low-fat milk in a biofilm model using the CDC Biofilm Reactor. Streptococcus mutans ATCC 25175 biofilms were formed on saliva coated bovine enamel slabs in a CDC Biofilm Reactor. Biofilms were exposed three times per day to one of the following materials: commercial whole milk (fat content: 3.4%), low-fat milk (fat content: 1%), or 0.9% NaCl. Medium pH was measured at different time points. After 5 days, biofilms were separated from slabs to evaluate the CFUs. The biofilm thickness was observed by confocal laser-scanning microscopy (CLSM). Enamel slab's demineralization was assessed by measuring surface microhardness before and after the experiment. For microhardness and CFUs assessment, no significant difference was found among the three groups. All groups showed similar pattern of medium pH change and biofilm thickness. Our results showed that there was no difference in the cariogenicity between whole milk and low-fat milk. Both milks were relatively non-cariogenic compared to the control group.

• Journal of Food Hygiene and Safety
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• v.18 no.1
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• pp.14-24
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• 2003

Two aims of the present study were the evaluation of hygienic, microbial safety on food services of elementary schools in Western Gyeongnam province, and then, the construction of database for the SSOP (Sanitation Standard Operation Procedures) practice. A total of 98 samples were collected from drinking water, waterworks, kitchen utensils, kitchen equipments, employees and cooked foods. Total bacteria was counted and pathogenic bacteria such E. coli, salmonella, yersinia, vibrio parahaemolyticus and staphylococcus were identified based on the biochemical analysis. Following are the results: the number of bacteria showed from 1.0x10$^2$CFU/ mL to 1.0x10$^{6}$ CFU/mL in most samples, which the level exceeds normal range. Over 1.0x10$^{5}$ CFU/ml bacteria were observed from the kimchi in 4 places (B, C, D, E), because cooked food such as kimchi had not been heated. As a rule, the bacterium level in place B was higher than that in any of the other places. E-coli were isolated from kitchen knives (C, E) and Kimchi (E): staphylococci were isolated from drinking water (A), hands (D), refrigerator (E) and apron (E). But, salmonella, vibrio and yersinia were not detected in anywhere. In conclusion, the presence of bacteria and pathogenic agents in school food service was closely related to hygienic practice. For that reason, it is necessary to have more systematic and efficient management in order to enhance the food safety.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.3
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• pp.461-466
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• 2010

A cylindrical UV sterilization system was developed to decrease microorganisms in centrifuged Takju (CT). CT was run through 110 strips of honey comb type-teflon tubes and 9 UV lamps (1395 W) were equipped between teflon tubes. The optimum sterilization condition of CT was fixed for 1.5 min at 2 L/min in overall quality aspects; also, 5~6 log cycle decrease of viable cell numbers of total bacteria and yeast was observed at this operating condition. Quality changes of UV-sterilized CT were examined by UV irradiation of CT followed by storing at $30^{\circ}C$ for 8 days. To evaluate quality changes of UV-sterilized CT, pH, amino nitrogen content, acidity, reducing sugar content and viable cell numbers of total bacteria and yeast were measured. The growth of yeast and bacteria was retarded, showing around $10^8\;CFU/mL$ even after 4 days and $10^8\;CFU/mL$ after 6 days, respectively. Also, UV sterilized CT showed no changes in pH, titratable acidity, and amino nitrogen content during storage except reducing sugar content. UV sterilization did not cause significant difference in L, a, and b values between CT and UV-sterilized CT over the storage period.

• Korean Journal of Microbiology
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• v.43 no.1
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• pp.14-18
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• 2007

The bacterial community structures at 2 sponge species belonging to the genus Baikalospongia and Lubomirskia in Lake Baikal were analyzed with fluorescent in situ hybridization (FISH) method. The total bacterial numbers in the genus Baikalospongia ranged from $7.2{\times}10^{7}\;to\;4.2{\times}10^{8}\;cells/ml$, and those in Lubomirskia from $1.2{\times}10^{8}\;to\;1.6{\times}10^{8}\;cells/ml$, while those of lake water were from $2.3{\times}7.7{\times}10^{5}\;cells/ml$. Total bacterial numbers in the sponges were $10^{3}-10^{4}$ times higher than those of lake water. In the genera Baikalospongia and Lubomirskia, the proportions of other unidentified bacterial groups to the Bacteria were 42.0-60.3% and 40.7-51.9%, respectively. These proportions were similar to those in lake water (22.6-46.3%). These results suggest that bacterial compositions in Lake Baikal water and sponges are highly unique.

• Journal of Food Hygiene and Safety
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• v.1 no.2
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• pp.151-156
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• 1986

A trial was carried out to check the seasonal variation in total bacterial counts (T.B.C.) and psychrotrophic bacterial counts (P.B.C.) and to investigate the quality deterioration of raw milk collected from dairy farms in Kyunggi area, Korea. T.B.C. of raw milk exceeded $10^{7}/ml$ in summer and $10^{6}/ml$ in winter 1980, but they have gradually decreased from 1983. In 1985, the counts showed less than $2{\times}10^{6}/ml$ through the whole year. The same tendency of improvement in coliform counts was shown. The counts were higher than $10^{6}/ml$ in summer and $10^{5}/ml$ in winter 1982, but they were kept lower than $1{\times}10^{5}/ml$ in 1985 through the whole year. Free fatty acids and free amino acids were increased in raw milk stored at $5^{\circ}C\;and\;10^{\circ}C$, by the growth of psychrotrophic bacteria.

• KOREAN POULTRY JOURNAL
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• v.36 no.2 s.412
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• pp.151-153
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• 2004

세균성 감염 관절염은 활액막염(synovitis)으로서 활액막에 염증이 생겨 발병하게 된다. 일반적으로 관절염과 건초염(tenosynovitis)은 동시에 발생하는 경향이 있으며, 관절염이 발병한 브로일러 종계는 결국 도태시킬 수밖에 없다.

• Journal of Food Hygiene and Safety
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• v.34 no.6
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• pp.534-541
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• 2019

his study assessed microbial contamination of leeks and leek-cultivated soil. Leeks and leek-cultivated soil were collected in A and B regions and accounted for 39 and 33 samples, respectively. All of the samples were analyzed for the presence of sanitary indicator bacteria (total aerobic bacteria, coliforms and Escherichia coli), Salmonella spp., E. coli O157:H7, Listeria monocytogenes, and Bacillus cereus. In A and B region, the total aerobic bacteria was in the range of 5.87-8.78 log CFU/g for leeks and 5.94-8.45 log CFU/g for leek-cultivated soil. The coliform in leeks and leek-cultivated soil was in the range of 1.20-7.36 log CFU/g and 2.45-5.87 log CFU/g, respectively. B. cereus was detected from some of the samples while other pathogens were not detected. This study provides important background information on the microbiological safety of fresh vegetable cultivation environments.

• Journal of Food Hygiene and Safety
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• v.36 no.6
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• pp.493-503
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• 2021

The study was designed to analyze raw and auxiliary materials of Korean traditional cookies such as Yugwa and Gangjeong, equipment and tools, personal hygiene of workers and microbial contamination of materials by each manufacturing process. In addition, it looked at washing method for reducing microorganisms at the site and reduction effect of microorganisms by frequency in the manufacturing processes of Yugwa. In the process of producing Korean traditional cookies, the level of total aerobic bacteria (TAB) in popped rice was 1.2 Log CFU/g and the level of TAB in finished products increased to 3.7 Log CFU/g. In the process of producing Yugwa, the level of TAB increased to a maximum of 6.5 Log CFU/g in the soaking process but decreased to 1.3 Log CFU/g in the frying process. However, the level of TAB increased again to 1.3 Log CFU/g in finished products that proves its recontamination. It is estimated that he manufacturing process causes cross-contamination that comes from the work tools, equipment or workers. In particular, the spatula, one of the work tools, was found to have 4.4 Log CFU/g of aerobic bacteria and 4.2 Log CFU/g of colon bacillus that show they are highly contaminated. In the soaking process of Yugwa that lasts seven days, the level of TAB was a maximum of 10 Log CFU/g and the level of total colon bacillus was 6.8 Log CFU/g. When compared with washing methods, using hands and tools or running water, it is confirmed that the level of both TAB and total colon bacillus decreased to 5.0 Log CFU/g and 2.8 Log CFU/g respectively when hands were washed with running water 10 times. The above result shows that it's required for workers to wash their hands as well as wash and disinfect work tools and equipment in the process of producing Korean traditional cookies at small-scale companies. In addition, to reduce the level of microbial contamination in finished products, workers are required to apply their reduction method at the site.

• Journal of Preventive Medicine and Public Health
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• v.22 no.2 s.26
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• pp.268-275
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• 1989

The studies on the standard plate count, most probable number(MPN) and isolation of the Enterobacteriaceae, especially Salmonella species from stream waters of Kyong-Ju city were carried out from June to July, 1988. The relationship between water temperature, weather and standard plate count were observed. The locations where all of the MPN was higher than 1,600 were Mun-chon bridge, Wol-song bridge, Go-hun bridge and the area adjoining the Hyong-san river. The higher the water temperature, the more the viable counts without rain. Bacteriological survey of the Salmonella species was performed with the total 80 specimens isolated from 16 areas which are the main streams in Kyong-Ju city. The author identified S strains(2.36%) of Salmonella typhi, 5 strains(2.3%) of Salmonella paratyphi, 2 strains(1.42%) of Salmonella paratyphi B, 63 strains(29.72%) of other Salmonella groups by biochemical tests and serotyping tests with slide agglutination.

• Journal of Food Hygiene and Safety
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• v.17 no.4
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• pp.173-177
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• 2002

It was performed to survey bacterial distribution on 72 salted fermented fishery products in Seoul Garak wholesale market from April to May in 2002. In average values of biological aspects, salts were 17.2%, in microbiological aspects (Unit: CFU/ml, bacterial cell count 4,900, coliforms 44, Vibrio spp., 160, Staphylococcus spp., 3,000 respectively. Of 93 isolated cells, coliforms were 35.5% (33/93), Vibrio spp. 8.6% (8/93) and Staphylococcus spp. 12.9% (12/93). E. cloacae was the highest (15/33) in coliforms, V. alinolyticus were the most (each 5/8) in Vibrio spp., In case of Staphylococcus spp., S. lentus was the best (5/12).