• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.779-785
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• 1996

Sansung takju, the Korean traditional liquor at a local area of Sansung in Pusan, has been widely drunken due to its tradition in this area. The studies on microorganisms of kokja, fermentation process and shelf-life of takju were carried out. The most abundant microorganism identified from a commercial Sansung kokja was Aspergillus, Mucor, Rhizopus and Penicillium were also identified. In case of a home-made Sansung kokja, Mucor was the most abundant one. Aspergillus, Rhizopus and Absidia were also identified in it. Saccharomyces, Micrococcus and Bacillus were identified in both kokja's but acid production bacteria were not found. Ethanol fermentation was carried out at $25^{\circ}C$ and $30^{\circ}C$ using each kokja. The rate of ethanol production was faster at $30^{\circ}C$ than at $25^{\circ}C$, while higher viable yeast count and final ethanol content were obtained at $25^{\circ}C$ than at $30^{\circ}C$. The ethanol contents of the mashes using a commercial Sansung kokja and a home-made Sansung kokja after 14 days at $25^{\circ}C$ were 11.0% and 12.4%, respectively. The shelf-life of takju was affected more by ethanol content in the product than by storage temperature. The product stored at $-15^{\circ}C$ did not change significantly in acidity but tasted watery due to thawing. In case of Sansung takju containing 6%ethanol, level of acidity increased and pellicle was formed on the surface of the product during storage at $30^{\circ}C$. In case of Sansung takju containing 9% or 12% ethanol, no significant changes in acidity and appearance were observed for 14 days at $30^{\circ}C$.

• Journal of Environmental Health Sciences
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• v.43 no.2
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• pp.143-156
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• 2017

The purpose of this study was to investigate water quality through a field survey at six floor fountain sites. The floor fountain facilities were designed and operated in such a way that tap water was stored in a water tank and recycled repeatedly. The water tank was cleaned once or twice per week in the summer. The number of facility users was low during the day due to sweltering heat, but up to 40 people, mainly children, were using them around 8 pm. Since the operation time was as short as 30 minutes, it is considered necessary to extend it for at least one hour for the number of users. As a result of the water quality test of the reservoir tank prior to operation after cleaning, it was measured to be within drinking water quality standards at the six facilities. As a result of the water quality test after use, ammonia nitrogen was measured to be 1.45 mg/L at Site IV. This exceeded the drinking water quality standard of 0.5 mg/L. In the case of turbidity, two cases exceed at 7.38 and 4.52 NTU when applying 4 NTU as the water quality standard for waterscape facilities. Twenty-eight cases exceed the standard of drinking water quality. The result of microbiological tests, at five sites excepting Site I, where disinfectant was injected, was that the maximum total colony count was 180,000 CFU/mL, total coliforms was 2,100,000 CFU/100 mL, fecal coliforms was 4,600 CFU/100 mL, Escherichia coli was 170 MPN/100 mL and Enterococcus was 100 CFU/100 mL. This exceeded the water quality standards of drinking water. Children are very likely to inhale because the water spews from below and falls from above, so it is necessary to apply water quality standards for ammonia nitrogen, turbidity and microbes. Current floor fountain facilities are highly susceptible to disease caused by microbial contamination because of water cycling and reuse, so it is necessary to change the water every day, clean the water tank, and perform chlorination. Therefore, it is necessary to inject calcium hypochlorite according to the free chlorine water quality standard of swimming pools with a different water tank capacity. In addition, facilities should be improved to prevent the reuse of water by installing the water tank at a separate location.

• Korean Journal of Microbiology
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• v.38 no.4
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• pp.247-253
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• 2002

The cellular responses of TNT-degrading bacterium, Stenotrophomonas sp. OK-5 to explosive 2,4,6-trini-trotoluene (TNT) as an environmental contaminant were examined. Survival of the strain OK-5 with time in the presence of different concentrations of TNT under sublethal conditions was monitored, and viable counts paralleled the production of the stress shock proteins in this bacterium. Total cellular fatty acids analysis showed that strain OK-5 produced or disappeared several different kinds of lipids when grown on TNT media than when grown on TSA. Under scanning electron microscope, the cells treated with 0.5 mM TNT for 12 hrs showed irregular rod shapes with wrinkled surfaces. Analyses of SDS-PAGE and Western blot using anti-DnaK and anti-GroEL revealed that several stress shock proteins including 70 kDa DnaK and 60 kDa GroEL in strain OK-5 were newly synthesized at different TNT concentrations in exponentially growing cultures. 2-D PAGE of soluble protein fractions from the culture of OK-5 exposed to TNT demonstrated that approximately 300 spots were observed on the silver stained gel ranging from pH 3 to pH 10. Among them, 10 spots significantly induced and expressed in response to TNT were selected and analyzed. As the result of internal amino acid sequencing with ESI-Q TOF, two proteins, spot #1 and spot #10 were assigned the DnaK protein XF2340 of Xylella fastidiosa and stress-induced protein of Mesorhizobium loti, respectively.

• Korean Journal of Microbiology
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• v.50 no.3
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• pp.191-200
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• 2014

Gas hydrates play a significant role in the global carbon cycle and climate change because methane, a greenhouse gas, can be released from the dissociation of gas hydrate. Anaerobic oxidation of methane (AOM) is an important process that consumes more than 90% of the methane released into the hydrosphere and atmosphere. In this study, the microbial community associated with the methane gas hydrate sediment in the Ulleung basin, East Sea of Korea (UBGH) was analyzed by phylogenetic analysis of the mcrA and 16S rRNA gene libraries. A vertical stratification of the dominating anaerobic methane oxidizer (ANME)-1 group was observed at the surface and the sulfate methane transition zone (SMTZ). The ANME-2c group was found to be dominant in the high methane layer. The archaea of marine benthic group B, which is commonly observed in the AOM region, accounted for more than 50% of the identifications in all sediments. Nitrate reducing bacteria were predominant at SMTZ (Halomonas: 56.5%) and high methane layer (Achromobacter: 52.6%), while sulfate reducing bacteria were not found in UBGH sediments. These results suggest that the AOM process may be carried out by a syntrophic consortium of ANME and nitrate reducing bacteria in the gas hydrates of the Ulleung Basin of the East Sea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.205-211
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• 2006

Jeung-pyun was irradiated at 0, 5, 10 kGy and pH, reducing sugar, microbiological quality, texture profile analysis and sensory quality were investigated during storage for 2 weeks at $25^{\circ}C$. Irradiation significantly reduced total bacteria counts and indicated an increase in hardness with increasing irradiation dose. Treatments with 5, 10 kGy did not cause significant change in the PH, reducing sugar, but pH, reducing sugar, microbacterial counts in 0 kGy were increased during storage. Main putrefactive microorganisms of Jeung-pyun were identified as Bacillus subtlis. In texture profile analysis, cohesiveness and chewiness of all irradiated samples were observed to reduce during storage. In the result of sensory evaluation, the irradiated samples had higher scores than non-irradiated samples after 4 days.

• Journal of Food Hygiene and Safety
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• v.14 no.1
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• pp.1-8
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• 1999

There were few data for the distribution of the indicator organisms in the commercial plant foods, and for the normal flora and for the foodborne agents within the country. First of all it must be investigated the distribution of the indicator organisms. And also it is very important to prepare the sanitation criteria for the plant foods through the microbiological examination and the investigation of tendency to change of the indicator organisms according to the storage temperature and period. The average number of total viable counts for grains was 2.9$\times$105/g, psychrophilic bacteria 2.9$\times$105/g, heterotrophic bacteria 3.1$\times$105/g, heat-resistant bacteria 2.1$\times$103/g, Pseudomonas aeruginosa 23/g. That for beans was 6.3$\times$102/g, psychrophile 34/g, heterotroph 1.7$\times$102/g. That for sesames was 1.4$\times$105/g, coliform 350/g, psychrophile 7.4$\times$104/g, heterotroph 5.8$\times$104/g, Pseud. aeruginosa 2.3$\times$103/g. heat-resistant bacteria 150/g. That for potatoes was 2.0$\times$107/g, coliform 5.0$\times$104/g, psychrophile 1.8$\times$107, heterotroph 1.4$\times$107/g, heat-resistant bacteria 3.3$\times$104/, Staphylococcus 2.7$\times$105/g, fecal streptococcus 4.5$\times$103/g, Pseud. aeruginosa 7.0$\times$103/g. That for mushrooms was 1.2$\times$108/g, psychrophile 9.4$\times$107/g, heterotroph 1.0$\times$109/g, heat-resistant bacteria 1.6$\times$105/g, Pseud. aeruginosa 1.3$\times$103/g. That for vegetables was 5.9$\times$1011/g, coliform 1.8$\times$106g/, Staphylococcus 1.1$\times$1012/g, heterotroph 8.4$\times$1011/g, heat-resistant bacteria 7.6$\times$106/g, Staphylococcus 1.1$\times$107/g, fecal streptococcus 1.1$\times$104/g, Pseud. aerugniosa 5.2$\times$104/g. That for nuts 3.9$\times$104/g, coliform 3.9$\times$103/g, psychrophile 4.0$\times$104/g, heterotroph 3.2$\times$104/g, heat-resistant bacteria 400/g. In commercial grains and beans, SPC, psychrophile, heterotroph and heat-resistant bacteria stored at 1$0^{\circ}C$, 2$0^{\circ}C$, 3$0^{\circ}C$ were constant. Staphylococcus, coliform, Pseud. aeruginosa were decreased a little n grains, but were not detected in beans. In mushrooms, all indicator organisms were increased as time goes on and were increased rapidly at 2$0^{\circ}C$. In sesames, coliform was not detected at all temperature. psychrophile was increased for 7 days, the others were constant. In potatoes, SPC, psychrophile, heat-resistant bacteria, heterotroph had a tendency to increase and the others were constant. In vegetables, indicator organisms were had a tendency to increase, psychrophile, heterotroph were rapidly increased after 7 days. In nuts, SPC, coliform, psychrophile heterotroph, heat-resistant bacteria, Pseud. aeruginosa were constant, staphylococcus and fecal streptococcus were not detected.

• Food Science of Animal Resources
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• v.28 no.1
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• pp.32-38
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• 2008

In order to expand the use of hog liver by the food industry, spreadable liver product was manufactured and quality changes were investigated depending on storage temperature at $-2^{\circ}C,\;5^{\circ}C\;and\;20^{\circ}C$ for 30 days. pH, thiobarbituric acid (TBA), volatile basic nitrogen (VBN), color, microbiological and sensory evaluation were carried out. Changes in pH values were not significantly different at different storage temperatures. TBA values were 0.6 mg MA/kg at $-2^{\circ}C$ after 30 days, 0.80 mg MA/kg at $5^{\circ}C$ after 21 days and showed 0.91 mg MA/kg at $20^{\circ}C$ after 14 days. The change in VBN content tended to increase during prolonged storage periods regardless of storage temperature. The product color tended to lighten over time, although there was no difference in a value of color during storage periods. Also, sensory evaluation results showed that the optimal storage temperature for the liver product was $5^{\circ}C$. The numbers of general bacteria increased to a level of 7.38 log CFU/g on storage 7 days in $20^{\circ}C$. This study showed that a viable spreadable liver product could be manufactured using hog liver and remains edible for at least 14 days when stored at temperatures below $5^{\circ}C$.

• Korean Journal of Microbiology
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• v.39 no.4
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• pp.272-276
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• 2003

Sapgyo Lake is an artificial freshwater reservoir which is located to the midwest of Korea and is the main water reservoir for industry and agriculture of the region. In this study we investigated environmental factors and the change of bacterial community with the influence of surrounding inflow water and the seasonal variation using the molecular ecological approach. Water samples were collected at front of the dike in May and August, 2001. Bacterial genomic DNAs were extracted directly and purified for the amplification of bacterial 16S rDNA. Clone libraries of the 16S rDNA were constructed using pGEM-T easy vector and RFLP analysis was performed to make a group as OTUs with 4 base recognizing enzymes (MspI and HaeIII). The estimated values of richness in August sample was higher than in May. Thirty-three of 153 clones in May and thirty-eight of 131 clones in August were sequenced from forward region of bacterial 16S rDNA for about 600~800 bp. Proteobacteria, Cytophaga, gram positive bacteria and Verrucomicrobia were observed both months. Especially, Planctomyces, cyanobacteria and chloroplast appeared in August when algal bloom occurred. On the whole investigation, Sapgyo lake showed a typical community structure of estuarine and was influenced by heterochthonous organic matters from the surrounding stream.

• Korean Journal of Microbiology
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• v.37 no.1
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• pp.72-79
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• 2001

The effect of phenol on the change of bacterial community in the effluent water from a wastewater treatment plant was analyzed by PCR and terminal restriction fragment length polymorphism (T-RFLP). The fragments of 16S rDNA were amplified by PCR with bacterial primers, where one of the primers was biotinylated at the 5'-end. After digestion with restriction enzymes, HaeIII and AluI, the biotinylated terminal restriction tragments (T-RFs) of the digested products were selectively isolated by using streptavidin paramagnetic particles. The single-stranded DNA of T-RFs was separated by electrophoresis on a polyacrylamide gel and detected by silver staining technique. When 10 standard strains were analyzed by our method, each strain had a unique T-RF which corresponded to the calculated size from the known sequences of RDP database. The T-RFLP fingerprint generated from the effluent water was very complex, and the predominant T-RFs corresponded to members of the genus Acinetobacter, Bacillus and Pseudomonas. In addition, the perturbation of bacterial community was observed when phenol was added to the sample at the final concentration of 250 $l^{-1}$. The number of T-RFs increased and the major bacterial population could be assigned to the genus Acinetobacter, Comamonas, Cytophaga and Pseudomonas. A intense band assigned to the putative genera of Acinetobacter and Cytophaga was eluted, amplified, and sequenced. The nucleotide sequence of the T-RF showed close relationship with the sequence of Acinetobacter junii.

• Korean Journal of Microbiology
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• v.51 no.1
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• pp.61-67
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• 2015

Recently, change of Western pattern diet and lifestyle is caused by various metabolic disorders and chronic diseases. These diseases need to take medicine regularly. Also, many people take health functional food, various vitamins and nutritional supplements in order to maintain a healthy life. But, there was no study about affects taking medicines against bacteria with gastrointestinal relevance. This study was performed by antibacterial activity test to evaluate the influence of a long time or commonly used medication. As a result, medicines of Vitamins & Minerals or Central nervous system show antibacterial activity against beneficial enteric bacteria and harmful enteric bacteria. Dexibuprofen of the Anti-inflammatory Drugs that acts on the central nervous system has shown high antibacterial activity at beneficial enteric bacteria strains (Lactobacillus casei, Lactobacillus rhamnosus) and harmful enteric bacteria (Staphylococcus aureus). Also, fenofibric acid of the antilipemic agents that acts on the Cardiovascular & Hematopoietic system has shown high antibacterial activity at beneficial enteric bacteria strains (Lactobacillus casei). Vitamins & Minerals appeared antibacterial activity against most intestinal bacteria. Vitamin B-Complex/with C and vitamin C were especially high with beneficial enteric bacteria strains (Bifidobacterium infantis) and harmful enteric bacteria (E. coli, E. aerogenes, S. flexneri, S. Typhimurium, S. aureus). Therefore, these results indicate that variously taking medicines have generally antibacterial activity against harmful enteric bacteria strains and beneficial enteric bacteria strains.