• Journal of Food Hygiene and Safety
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• v.12 no.4
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• pp.346-353
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• 1997

This study was undertaken to find out distribution and contamination sources of hazardous microbes through microbial hazard analysis on the processing steps of surimi-based imitation crab (SBIC). As a results of ananlysis of 9 hazardous microbes for 16 raw materials and 8 processing steps, no Samonella spp. and Escherichia coli were detected in all samples. Level and distribution of hazardous microbes in mixed color were similar to those of surimi. Changes of aerobic plate counts (APC), psychrotropic bacteria, coliforms, Staphylococcus aureus and Vibrio parahaemolyticus showed similar trends at different processing steps. Thermotrophic bacteria and aerobic sporeformers were not detected until mixing step and feeding step, respectively and not reduced after cooking step. According to the comparison of APC at each step, it was suggested that surimi, workers and silent cutter at mixing step, and mixed color, workers and bundler at packaging step were the major contamination sources of bacteria.

• Food Science and Preservation
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• v.3 no.2
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• pp.145-148
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• 1996

This paper was carried out to investigate change in the initial microorganism of Pepper which were treated with ozonated water for microbial decontamination. When ozonated water was 30, 60, 90minutes treatment, there was decrease in the overall total microbial of the black & white pepper. Total lactic acid bacteria died completely after contacted with ozonated water for 60minutes but the inhibition rate on the total aerobic bacteria of black & white pepper were 62% and 96%, respectively. Total aerobic bacteria of four packing material was increased after 1 months of storage at 37$^{\circ}C$ when it had treated with 90minutes ozone reaction Then, there was no significant changes in the piperin contents.

• Korean journal of food and cookery science
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• v.28 no.5
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• pp.599-604
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• 2012

In this study, the prevalence of microbiological hazard on water purifiers at lunchroom in child care center was investigated. A total of 49 water purifiers and their purified cold water were sampled to test about the total aerobic bacteria, coliform bacteria, Bacillus cereus, Staphylococcus aureus, and Salmonella spp. Total aerobic bacteria was detected over 2.0 log CFU/mL in 6 out of 49 purified cold water (12.2%), ranged from 2.0 to 2.4 log CFU/mL, and the average number of total aerobic bacteria was showed to be 3.3 log CFU/drain spout. The drain spout turned out to be a major contaminant in water purifier and needs to be improved. Coliform bacteria were also detected in 7 out of 49 cold faucets (14.3%) and 7 out of 49 drain spouts (14.3%), but not detected in purified cold water. All samples were not contaminated with the pathogens tested in this study, except for B. cereus, which was contaminated on 2 out of 49 cold faucets (4.1%) and 4 out of 49 drain spouts (8.2%). All of B. cereus isolates produced enterotoxin, such as heamolysin BL enterotoxin (HBL) or non-heamolytic enterotoxin (NHE). The HBL was detected in 5 out of 6 B. cereus isolates (83.3%), including B. cereus PCF-11 and B. cereus PDS-30 isolate only produced NHE (16.7%). These results showed that the sanitary conditions of cold faucets and drain spouts should be improved promptly.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.4
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• pp.247-253
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• 2014

In the silage quality, the process of fermentation and use of micro-organism as starter cultures are crucial. The present study investigated the effect of homo and heterofermentative lactic acid bacteria as a starter culture strain on the silage quality and its aerobic stability using meta-analysis. Total 19 studies were used in the analysis. According to the strains of lactic acid bacteria used, experimental groups were assigned to heterofermentative (HEL), mixture of hetero and homofermentative (HHO), homofermentative (HOL) and various homofermentative (HOM). In each experimental group, standardized result of the treatment (with inoculant) was compared with the control (without inoculant) using risk ratio calculation method. The effect of experimental group was also compared. Different starter culture strains did not influence on silage pH and propionic acid production. However, lactic acid and acetic acid production were significantly (p<0.05) influenced by the start culture strains. HOM showed the greatest lactic acid production and HEL was the lowest. In contrast, HEL showed the greatest in acetic acid production and HOM and HOL were the lowest. In terms of ammonia nitrogen, HHO produced more (p<0.05) than the rest of the treatment. In crude protein and water soluble carbohydrate contents, there were no significant effects among treatments. Different strain of lactic acid bacteria significantly influenced on the effect of aerobic stability (p<0.05). Use of heterofermentative showed greater aerobic stability and the use of homofermentative lactic acid bacteria.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.4
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• pp.497-505
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• 2005

Domestic Sewage Treatment Plants are mostly based on biological treatment, in which large amounts of excess sludge are generated and occupy about 40 ~ 60% of the total sewage treatment costs. Several methods for sludge treatment has been so far reported as upgrading biodegradation of sludge; heat treatment, chemical treatment, including thermo-alkali and ozone, mechanical treatment including ultrasonic pulverization. But, it has a limitation in case of reducing the amount of excess sludge which are already producted. In this study, application of excess sludge reduction process using thermophilic aerobic bacteria for activated sludge was examined. The research was carried out two different stage. one for a biological wastewater treatment and the other for a thermophilic aerobic solubilization of the waste sludge. A portion of excess sludge from the wastewater treatment step was into the thermophilic aerobic sludge solubilization reactor, in which the injected sludge was solubilized by thermophilic aerobic bacteria. The solubilized sludge was returned to the aeration tank in the wastewater treatment step for its further degradation. Sludge solubilization reactor was operated at $63{\pm}2^{\circ}C$ with hydraulic retention time(HRT) of 1.5 ~ 1.7 day. Control group was operated with activated sludge process(AS) and experiment group was operated with three conditions(RUN 1, RUN 2, RUN3). RUN 1 was operated with AS without sludge solubilization reactor. RUN 2 were operated with AS with sludge solubilization reactor to examine correlation between sludge circulation ratio and sludge reduction ratio by setting up sludge circulation ratio to 3. RUN 3 was operated with sludge circulation ratio of 3 and MLSS concentration of 1,700~2,000mg/L to examine optimum operation condition. The quantity of excess sludge production was reduced sharply and in operation of RUN 3, sludge The quantity of excess sludge production was reduced sharply and in operation of RUN 3, sludge solubilization ratio and sludge reduction ratio were 53. 7%, 95.2% respectively. After steady state operation, average concentration of TBOD, SBOD, $TCOD_{Cr}$, $SCOD_{Cr}$, TSS, VSS, T-N, T-P of effluent were 4.5, 1.7, 27 .8, 13.8, 8.1, 6.2, 15.1, 1.8mg/L in the control group and were 5.6, 2.0, 28.6, 19.1, 9.7, 7.2, 16.1, 2.0mg/L in the experimental group respectively. They were appropriate to effluent standard of Sewage Treatment Plants.

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.382-388
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• 2002

In order to assess the effects of organic fertilizer on soil microbial community structure and diversity in the greenhouse fields, fatty acid methyl ester (FAME) was analyzed by the MIDI (Microbial ID, Inc., Newark, DE, U.S.A.) system and enumerations were performed. In relation to bacterial division of each sample, low GC Gram-positive bacteria were predominant among bacteria cultured on aerobic bacteria media. On the other hand, alpha subdivision was predominant on proteobacteria of control and OM (organic matter) 1 treated plot, and Flavobacterium spp. existed in OM2 plot on crystal violet media of all samples. Shannon-weaver Index (H) of OM1 plot varied most by 1.9 and 5.0 among bacteria cultured on aerobic bacteria media and crystal violet media, respectively. Our results revealed that addition of the organic wastes to soil led to a highly diverse microbial community, but the excessive amounts of organic and mineral fertilizer applied in the greenhouse fields produced excess nutrients in soil and led to simplification on bacterial populations.

• Journal of Life Science
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• v.9 no.5
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• pp.510-517
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• 1999

For the treatment of Korean food-wastes, three mesophilic and one thermophilic bacteria were isolated from soil and fermented fertilizers. The thermophilic Streptomyces sp. strain WF021 produced two enzymes which were a protease and a lipase at 55$^{\circ}C$. The mesophilic Bacillus sp. strain WF024 produced four enzymes which were a protease, a lipase, a amylase and a cellulase when the strain was grown both at 3$0^{\circ}C$ and 55$^{\circ}C$. The Bacillus sp. PY123 had produced three enzymes which were a protease, a cellulase and a lipase at 3$0^{\circ}C$. The Bacillus sp. strain CM1 produced three enzymes which were a protease, a amylase, and a cellulase at 3$0^{\circ}C$. The bacteria were grown in media containing 6% NaCl at least and did not have antagonism each other. The four isolates treated much more food-wastes than referance strains did. In a flask without aeration, three reference strains treated 15.4% of food-wastes, while four isolates treated 23.7% of food-wastes. In a flask with aeration, food-wastes were treated 67.3% by four isolates, and 64.3% by three reference strains, but 53.9% without bacteria. However, food-wastes were treated about 78% in a 200$\ell$-reactor made by Siwon Co., while 65.8% in a 20$\ell$-reactor made by Sanyo Co.

• Korean Journal of Food Science and Technology
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• v.20 no.3
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• pp.357-362
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• 1988

Twenty-one aerobic bacteria were isolated from Kimchi and the influences of aqueous extract of garlic on the isolates were studied. The bacteria were 11 Bacillus spp., 2 Staphylococcus spp., a Micrococcus sp., a Flavobacterium sp., an Enterobacteriaceae, and 4 Vibrionaceae. In nutrient broth growth of the bacteria was inhibited by the extract. The antibacterial effects of the garlic were different from each other depending upon the bacteria. The results revealed that the inhibitory effects were due to the bacteriocidal action of the garlic extracts.

• Journal of Environmental Health Sciences
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• v.34 no.1
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• pp.70-75
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• 2008

The Chinese cabbage kimchi, baechoo-kimchi, is the most popular type of kimchi in Korea. This study was performed to investigate the changes of index microorganisms (aerobic bacteria, psychrotrophilic bacteria, coliforms, and Escherichia coli), lactic acid bacteria, pH, and acidity of kimchi during the long-term fermentation and ripening. A homemade-style traditional Korean baechoo-kimchi, was prepared from Chinese cabbage, red pepper, green onion, garlic, ginger, and salt-fermented anchovy sauce, and then incubated at $10^{\circ}C$ for 28 days. In the baechoo-kimchi, the number of aerobic bacteria increased with time. The number of psychrotrophilic bacteria maintained their numbers $(10^4CFU/g)$ in the kimchi during the fermentation. Coliforms and E. coli were not detected in the kimchi. The pH of kimchi decreased and the acidity of kimchi increased over time. Lactic acid bacteria, which are representative of fermentative microorganisms in the kimchi process showed rapid growth in the earlier stage of fermentation and increased steadily after 7 days. The counts of lactic acid bacteria were at a level of $10^4CFU/g$ early in the fermentation stage, reaching a level of $10^8CFU/g$ after 14 days, and at this point pH was 4.18 and acidity reached 0.63, indicating that the optimal state of kimchi fermentation. This study suggests that the lactic acid bacteria which were proliferated in kimchi during the ripening and fermentation could contribute to improving the taste and flavor of kimchi and inhibit the growth of pathogenic microorganisms that might exist in kimchi.

• The Korean Journal of Ecology
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• v.18 no.3
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• pp.409-418
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• 1995

As a part of studying the function and structure of the mudflat environment of the Yellow Sea, seawater samples in the overlying waters of sediment near Daesan were collected every hour on March 29 (spring tides) and on April 5 (neap tides), 1995 to study the diurnal distribution of aerobic saprophytic bacteria and their extracellular enzyme activities. The diurnal distribution of aerobic saprophytic bacteria ranged from 1.0 X $10^{2}$ to 7.07 X $10^{3}$ cfu /ml at spring tides and from 1.0 X $10^{2}$ to 8.3 X $10^{3}$ cfu /ml at neap tides. The diurnal variations of aerobic saprophytes at the suface waters were greater than those of middle and bottom waters. However, th diurnal fluctuation of saprophyte numbers at spring tides showed no significant difference compared with that at neap tides. The numbers of three physiological groups of aerobic hacteria (proteolytic, lipolytic and amylolytic bacteria) at the surface waters during spring and neap tides were lower than those at the middles and bottom waters. The diurnal variations of five extracellular enzyme activities at the surface waters during the survey period showed lower values than those at the middle and botton waters. Among the measured extracellular enzyme activities, phosphatase showed the highest. However, the activities of amylase, chitinase and cellulase showed a similar tendency.