• Journal of Food Hygiene and Safety
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• v.35 no.2
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• pp.146-151
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• 2020

This study investigated microbiological safety of employees' hands, dining tables, and indoor air in cooking areas and lunchrooms in child care centers. Microbiological tests were performed according to the Korea Food Code. Total numbers of aerobic bacteria and coliform bacteria were measured as 5.8±1.9 log CFU/hand and 4.0±2.4 log CFU/hand on employees' hands, and 4.3±3.0 log CFU/100 ㎠ and 2.6±3.3 log CFU/100 ㎠ on dining tables. Bacillus cereus were detected in two cases each of employees' hands and dining tables, respectively. The analysis of microbiological contamination of indoor air in chid care centers showed that the total numbers of aerobic bacteria and coliform bacterial were 28±7.2 CFU/plate and 3.1±2.9 CFU/plate, respectively. Bacillus cereus and Staphylococcus aureus were counted as 1.7±0.2 CFU/plate and 1.6±0.5 CFU/plate from the indoor air in child cate centers. These results indicate that indoor-air in child care centers is considered more safe compared to previous reports. In conclusion, it is necessary to carry out hygienic management using alcohol-based disinfectants before meals to remove microorganism contamination on dining tables and hands. In order to reduce microbial contamination in indoor air, it is also deemed necessary to freshen the sanitary caps, masks, and clothing of the catering staff with periodic ventilation of indoor air.

• Journal of Microbiology
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• v.45 no.2
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• pp.113-121
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• 2007

The bacterial diversity inherent to the biofilm community structure of a modified rotating biological contactor wastewater treatment process, referred to as the Rotating Activated Bacillus Contactor (RABC) process, was characterized in this study, via both culture-dependent and culture-independent methods. On the basis of culture-dependent methods, Bacillus sp. were found to exist in large numbers on the biofilm (6.5% of the heterotrophic bacteria) and the microbial composition of the biofilms was quite simple. Only three phyla were identified-namely, the Proteobacteria, the Actinobacteria (High G+C Gram-positive bacteria), and the Firmicutes (Low G+C Gram-positive bacteria). The culture-independent partial 16S rDNA sequence analysis revealed a considerably more diverse microbial composition within the biofilms. A total of eight phyla were recovered in this case, three of which were major groups: the Firmicutes (43.9%), the Proteobacteria (28.6%), and the Bacteroidetes (17.6%). The remaining five phyla were minor groups: the Planctomycetes (4.4%), the Chlorobi (2.2%), the Actinobacteria (1.1%), the Nitrospirae (1.1%), and the Verrucomicrobia (1.1%). The two most abundant genera detected were the endospore-forming bacteria (31.8%), Clostridium and Bacillus, both of which are members of the Firmicutes phylum. This finding indicates that these endospore-forming bacteria successfully colonized and dominated the RABC process biofilms. Many of the colonies or clones recovered from the biofilms evidenced significantly high homology in the 16S rDNA sequences of bacteria stored in databases associated with advanced wastewater treatment capabilities, including nitrification and denitrification, phosphorus accumulation, the removal of volatile odors, and the removal of chlorohydrocarbons or heavy metals. The microbial community structures observed in the biofilms were found to correlate nicely with the enhanced performance of advanced wastewater treatment protocols.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.11
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• pp.1666-1672
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• 2003

The objective of this study was to evaluate the potential of an alumninosilicate clay, marketed under the trade name Biotite V, to improve growing-finishing pig performance and to determine its effects on nutrient digestibility and excretion. Sixty crossbred pigs (22.3${\pm}2.7kg$, Camborough 15 Line female${\times}$Canabred sire) were assigned on the basis of sex, weight and litter to one of four dietary treatments in a $2{\times}4$ (two sexes and four treatments) factorial design experiment. The experimental diets were based on barley and soybean meal and contained 0, 0.25, 0.5 or 0.75% biotite during the growing period (22.3-60.5 kg) and 0, 0.5, 1.0 or 1.5% biotite during the finishing period (60.5-110.3 kg). Each pig was allowed access to its own individual feeder for 30 min twice daily (07:00 and 15:00 h). Individual pig body weight, feed consumption and feed conversion were recorded weekly. The pigs were slaughtered at a commercial abattoir when they reached an average weight of 110.3 kg. Carcass weight was recorded and dressing percentage calculated. Carcass fat and lean measurements were obtained with a Destron PG 100 probe between the 3rd and 4th last ribs, 70 mm of the midline. Total tract digestibility coefficients for dry matter, energy, nitrogen and phosphorus were determined using three males and three females per treatment starting at an average weight of $52.2{\pm}3.8kg$. These pigs were housed under identical conditions as those used in the growing stage and were fed the same diets modified only by the addition of 0.5% chromic oxide as a digestibility marker. Over the entire experimental period (22.3-110.3 kg), daily gain was unaffected (p>0.05) by the inclusion of biotite in the diet. There was a cubic response for feed intake (p=0.06) and a quadratic response (p=0.07) for feed conversion due to biotite. Feeding biotite produced no significant (p>0.05) linear or quadratic effects on any of the carcass traits measured. Dry matter digestibility decreased linearly (p=0.02) with increasing levels of biotite in the diet. However, digestibility coefficients for energy, nitrogen and phosphorus were unaffected (p<0.05) by biotite inclusion. Lactobacilli and enterobacteria numbers were unaffected by inclusion of biotite while Salmonella was not detected in any of the fecal samples. The overall results of this experiment indicate that biotite inclusion did not reduce fecal excretion of nitrogen or phosphorus and failed to improve nutrient digestibility. Neither growth rate nor carcass quality was improved while a modest improvement in feed conversion was observed at lower levels of inclusion. Based on the results of this experiment, it would be difficult to justify the routine inclusion of biotite in diets fed to grower-finisher pigs. Whether or not a greater response would have been obtained with pigs of a lower health status is unknown.

• Journal of Korean Academy of Nursing
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• v.19 no.3
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• pp.240-248
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• 1989

The increase in size and numbers of general hospitals in the process of conspicuous development of modem medicine has been accompanied by a serious increase in hospital acquired infections. Hospital aquired infections cause pain and discomfort, may threaten life, adds an economic burden, and delays recovery and return to society. Even though respiratory hospital infection rates resulting for tracheostomy and respiratory inhalation therapy, may be low, they are serious because of their bad prognosis and high mortality rates. This study was designed to assess certain aspects of respiratory infections of patients with a tracheostomy and thus provide baseline data for further research related to preventive or therapeutic nursing interventions. The specific objectives were to determine the incidence of colonization in the trachea, clinical signs, type of colonized bacteria and sensitivity to antibiotics. Data were collected from July 1 to December 10, 1989 at two university Hospital in Seoul. Subjects were 20 patients with a tracheostomy admitted to the Intensive Care Unit or Cerebral Vascular Accident Center. Clinical signs related to respiratory infection were observed using a checklist based on previous study outcomes. Bacterial culture, sensitivity test to antibiotics, WBC counts and chest X-ray were also performed. Cultures were done on the day of tracheostomy, and on the third, fifth and seventh day. Cultures were then done on seventh days after the first colonization. The results were as follows : 1. The incidence of bacteria colonization in a week was 90%(18 patients) 50% (10/20 patients) on the day of tracheostomy, 70%(7/10 patients) on the third day, and 0% on the fifth day, and 33%(1/3 patient) on the seventh day. 3 of 18 patients (16.7%) were colonies of mixed growth isolated. 2. The observed clinical signs related to respiratory infection were high fever 38.9%(7 patients), prulent secretion 16.7%(12 patients) and infiltration seen on chest X-ray 33.3%(6 patients). 3. The total number of types of bacteria isolated among the 18 subjects was 21 ; gram negative 71.4%, gram postive 28.6%. The dominant bacteria type was Staphylococcus aureus(5 cases) for gram(equation omitted) and Pseudomonas aeruginosa(3 cases), Klebsiella (4 cases), Enterobacter(3 cases) for gram (equation omitted). The results of culture on 7th day after the first colonization, 6 cases showed same type of bacteria, 3cases showed different type of bacteria and 1 cases showed no growth. 4. The sensitivity tests to antibiotics showed that Pseudomonas aeruginosa and Staphylococcus were strongly resistant to most kinds of antibiotics, but Klebsiella and the rest of gram negative bacteria were moderately sensitive to antibiotics.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.779-786
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• 2012

Rhodiola sachalinensis fermentates by lactic acid bacteria were prepared using the adsorption process, and were investigated for changes of the main compounds and anti-oxidative activities during the adsorption and fermentation process. While the R. sachalinensis extract (RSE), which did not go through the adsorption process, showed little change in pH during fermentation and a significant reduction in the number of lactic acid bacteria, the pre-preparatory adsorption process was found to be helpful for promoting fermentation and for maintenance of bacterial numbers. The contents of total phenolic compounds mostly decreased during the adsorption process, but showed an increasing tendency to rebound during the fermentation process. The contents of salidroside and p-tyrosol in the RSE were 1153.3 mg% and 185.0 mg% respectively, and they did not significantly change after treatment with acid clay or bentonite as adsorbents, which were 1093.0 and 190.5 mg% by acid clay, and 882.2 and 157.3 mg% by bentonite. When the extract was fermented after treatment with acid clay or bentonite, the salidroside contents were decreased by 282.7 and 505.0 mg% respectively, but the p-tyrosol contents were increased by 714.0 and 522.4 mg% respectively. Compared to the DPPH radical scavenging activity of the RSE (66.8%) at the conc. of 0.1%, that of the fermented RSE, which went through adsorption process with acid clay or bentonite, was significantly increased to 79.4 and 72.7% respectively at the same concentration (p<0.05). Though fermentation by lactic acid bacteria was suppressed in the RSE, the results suggested that the adsorption process may promote fermentation without any change in the content of major active compounds. It is expected that fermentation by lactic acid bacteria could improve the antioxidant activity and various associated functionalities of R. sachalinensis.

• Korean Journal of Environmental Agriculture
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• v.32 no.2
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• pp.148-154
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• 2013

BACKGROUND: Genetically modified(GM) trigonal cactus(Hylocereus trigonus Saff.) contained a coat protein gene of cactus virus X (CVX), which conferred resistance to the virus, phosphinothricin acetyltransferase (bar) gene, which conferred herbicide resistance, and a cauliflower mosaic virus 35S promoter (CaMV 35S). This study was conducted to evaluate the possible impact of GM trigonal cactus cultivation on the soil microbial community. METHODS AND RESULTS: Microorganisms were isolated from the rhizosphere of GM and non-GM trigonal cactus cultivation soils. The total numbers of bacteria, and actinomycete in the rhizosphere soils cultivated GM and non-GM trigonal cactus were similar to each other, and there was no significant difference. Dominant bacterial phyla in the rhizosphere soils cultivated with GM and non-GM trigonal cactus were Proteobacteria, Uncultured archaeon, and Uncultured bacterium. The denaturing gradient gel electrophoresis (DGGE) profiles show a similar patterns, significant difference was not observed in each other. DNA was isolated from soil cultivated GM and non-GM trigonal cactus, we analyzed the persistence of the inserted gene by PCR. Amplification of the inserted genes was not observed in the soil DNA, which was collected after harvest. CONCLUSION(S): This result suggests that the GM trigonal cactus cultivation does not change significantly the microbial community.

• Korean Journal of Environmental Agriculture
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• v.32 no.2
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• pp.95-101
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• 2013

BACKGROUND: Rice (Oryza sativa) is the most important staple food of over half the world's population. This study was conducted to evaluate the possible impact of transgenic rice cultivation on the soil microbial community. METHODS AND RESULTS: Microorganisms were isolated from the rhizosphere of GM and non-GM rice cultivation soils. Microbial community was identified based on the culture-dependent and molecular biology methods. The total numbers of bacteria, fungi, and actinomycete in the rhizosphere soils cultivated with GM and non-GM rice were similar to each other, and there was no significant difference between GM and non-GM rice. Dominant bacterial phyla in the rhizosphere soils cultivated with GM and non-GM rice were Actinobacteria, Firmicutes, and Proteobacteria. The microbial communities in GM and non-GM rice cultivated soils were characterized using the denaturing gradient gel electrophoresis (DGGE). The DGGE profiles showed similar patterns, but didn't show significant difference to each other. DNAs were isolated from soils cultivating GM and non-GM rice and analyzed for persistence of inserted gene in the soil by using PCR. The PCR analysis revealed that there were no amplified protox gene in soil DNA. CONCLUSION(S): These data suggest that transgenic rice does not have a significant impact on soil microbial communities, although continued research may be necessary.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1392-1396
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• 1999

This work was to apply the microwave energy to HTST pasteurization of milk in order to prevent undesirable quality changes due to the fouling and overheating on the surface of heat exchanger. A continuous tubulartype microwave pasteurization system was designed using a domestic microwave oven(800w and 2,450MHz). Raw milk was HTST pasteurized$(at\;72^{circ}C\;for\;15\;sec)$ by three methods; by heating in a stainless steel tube immersed in a hot water bath(MP0), by heating in a microwave cavity to a desired temperature and then holding in a hot water bath(MP1) and by both heating and holding in a microwave cavity(MP2). The microbial quality based on the total plate count and Psychotrophic bacterial count was in the order MP0, MP2 and MP1 ; however, the quality difference was not significant(p<0.05) when the initial microbial numbers were involved in the statistical analysis. In addition, the three samples pasteurized by different methods showed the similar microbial quality based on the coliform count and phosphatase activity. The similar microbial quality of the three samples supports the potential use of microwave energy for the pasteurization of milk and other fluid food products.

• Korean journal of food and cookery science
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• v.25 no.1
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• pp.8-15
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• 2009

This study was carried out to examine changes in the quality characteristics of Aralia continentalis Kitagawa (AcK) Jangachi made with different $CaCl_2$ and seasoning treatments during storage at $4^{\circ}C$ for 6 months. The results exhibited there were no significant changes in pH, acidity, and salinity in the various samples. The numbers of total bacterial counts and lactic acid bacteria increased slowly during the early storage period and then increased rapidly in the third month. In the fifth month they reached their highest level near $6.6{\times}10^{6}cfu/ml$ and then decreased thereafter. The sample treated with $CaCl_2$ exhibited a higher degree of hardness than the untreated sample. Finally, the sensory characteristics of the AcK Jangachi were highly acceptable during the entire storage period in terms of color, smell, bitterness, texture, and general preference regardless of the $CaCl_2$ treatments.

• Korean Journal of Microbiology
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• v.44 no.2
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• pp.147-155
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• 2008

The diversity of sulfate reducing bacteria was investigated in different depths of sediments in Lake Sihwa, Korea and Lake Aha, China by PCR amplification, denaturing gradient gel electrophoresis (DGGE) and clone libraries targeting dissimilatory sulfite redectase (dsr) gene. In the analysis of DGGE band patterns, the community compositions of dsr gene in the sediments of both lakes were significantly different whereas bands in all depths of each environment revealed similar patterns. Bands from Lake Sihwa were produced much more than those from Lake Aha, demonstrating a higher diversity of dsr gene in Lake Sihwa. Total 68 clones containing dsr gene were obtained to analyze their sequences. Sequences from the sediment of Lake Sihwa were affiliated to Deltaproteobacteria, the Gram-positive thermophilic sulfate reducers belonging to the genus Desulforomaculum and archaeal thermophilic SRB belonging to the genus Archaeoglobus, whereas sequences from the sediments of Lake Aha were related to genus Desulfotomaculum. Clones retrieved from sediment of Lake Sihwa revealed a higher numbers than those of Lake Aha, demonstrating a higher diversity of dsr gene in Lake Sihwa. Most of clones (59%) were distantly related to the known cultivated SRB with $60\sim65%$ of similarity, which were clustered only the sequences from the environments showed less than 90% similarity. These habitat specific sequences suggested that the clustered dsr sequences represent species or groups of species that were indigenous to these environments. This study showed that these lakes have a specific bacterial communities having dsr gene distinct from those in other environments such as soil and marine ecosystems around the world.