• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.683-687
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• 2004

Raw beefs used fer Jangzorim production were evaluated fur contamination of pathogenic bacteria and microorganisms related to spoilage and food safety. Eleven groups of mesophilic, psychrotrophic, and anaerobic microorganisms, and total coliforms were selected to evaluate degree of food contamination. Nine strains including Bacillus cereus, Clostridium botulinum, C. perfringens, and Listeria monocytogenes were selected to evaluate incidences of pathogenic bacteria. Raw beefs harbored large populations of microorganisms, which decreased greatly after heat treatment. Psychrotrophic microorganisms were found to be more abundant than other microorganisms. B. cereus, C. perfringens, and L. monocytogenes were isolated from raw beefs, whereas C. botulinum, Escherichia coli O157:H7, Salmonella spp., Shigella spp., Staphylococcus aureus, and Yersinia enterocolitica were not isolated. Isoiates from Cereus selective agar, clostridium Perfringens agar, and Oxford agar were in 99.8, 99.9 and 98.6% agreements with B. cereus, C. perfringens, and L. monocytogenes at species level, respectively. B. cereus produced enterotoxin with CRET-RPLA method, whereas C. perfringens did not produce enterotoxin with PET-RPLA method.

• Food Science of Animal Resources
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• v.30 no.4
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• pp.590-596
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• 2010

Meat and meat products are a potential source of food-borne pathogens, including Staphylococcus aureus, Salmonella spp., Escherichia coli O157:H7, and Bacillus cereus. A sensitive and specific PCR assay for the detection of these pathogens in meat and meat products was developed in this study, as part of a broader effort to reduce the potential health hazards posed by these pathogens. Initially, PCR conditions were standardized with purified DNA. Under standard conditions, the detection level for PCR was as low as 10 pg of purified bacterial DNA. After overnight growth of bacteria in a broth medium, as few as $10^2$ CFU of bacteria were detected by PCR assay. The primers employed in the PCR assay were found to be highly specific for individual organisms, and evidenced no cross-reactivity with heterologous organisms. Additionally, the multiplex PCR assays also amplified some target genes from the four pathogens, and multiplex amplification was obtained from as little as 10 pg of DNA, thus illustrating the excellent specificity and high sensitivity of the assay. In conclusion, this PCR-based technique provides a sensitive and specific method for the detection of S. aureus, Salmonella spp., E. coli O157:H7, and B. cereus in meat and meat products.

• Food Science of Animal Resources
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• v.28 no.1
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• pp.99-104
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• 2008

A lactic acid bacterium showing growth inhibitory activity against Enterobacter sakazakii was isolated from bovine intestinal tracts. From biochemical and molecular biological studies, the isolate was identified and named as Enterococcus faecium JH95. This strain was resistant to kanamycin and streptomycin at a concentration of $100{\mu}g/mL$. E. faecium JH95 had high antimicrobial activity against food-borne pathogens such as Escherichia coli O157:H7, Listeria monocytogenes, Salmonella typhimurium, Staphylococcus aureus, and Clostridium perfrigens. The culture supernatant of this strain did not have antimicrobial activity. The culture broth of this strain failed to show the antimicrobial activity by heat treatment at $100^{\circ}C$ for 5 min or by pretense treatments for 2 hr. This result suggested that the putative antimicrobial substance produced by E. faecium JH95 is likely a protein which is not secreted into culture medium.

• Korean journal of food and cookery science
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• v.13 no.3
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• pp.330-337
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• 1997

The sensitivity of various pathogenic bacteria (Aeromonas hydrophila, Estherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus 196E, Salmonella typhimurium and Vibrio parahaemolyticus) to the spices, allspice, clove, oregano, and thyme, was tested. Tryptic soy broth (TSB) containing 0∼2% (w/v) of spices was inoculated with 10sup 5/∼10$\^$6/ cells/$m\ell$ of each bacterium and incubated at 35$^{\circ}C$ for 24 hr. The growth of pathogenic bacteria was inhibited with increasing concentrations of spices in the culture broth. At 2％ spice concentration, Gram positive bacteria were more sensitive than Gram negative bacteria with the exception of V. parahaemolyticus. Clove had the highest antibacterial activity, followed by allspice and oregano. At the concentration of 0.3%, clove inhibited the growth of all strains tested. Kanagawa-positive strain of V. parahaemolyticus displayed the highest sensitivity to clove and allspice. Thyme was the least effective for growth inhibition, while 1％ clove killed all pathogens tested.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.639-642
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• 2006

The root extract of Scilla scilloides (which has been used as a traditional folk medicine in Korea) was evaluated with regard to antimicrobial, anti-inflammatory, and anti-oxidative activities. The roots of S. scilloides were minced and extracted with 95% ethanol (root:ethanol=25:75, w/v). The inhibitory effects of S. scilloides root extract on the growth of Staphylococcus aureus ATCC 35556, Salmonella enteritidis ATCC 12021, Escherichia coli O157:H7, and Candida parapsilosis KCCM 35428 were tested. The results indicate that the antimicrobial effects of both 0.1 and 1.0% extract of S. scilloides were greater against the growth of S. aureus ATCC 35556 and C. parapsilosis KCCM 35428 than the growth of S. enteritidis ATCC 12021 and E. coli O157:H7. The anti-inflammatory effects were evaluated by measurement of the inhibition of hyaluronidase activity in vitro. It appears that both 0.1 and 1.0% concentrations of extract have inhibitory effects on hyaluronidase relative to the control. Finally, the anti-oxidative effect of 1.0 and 10% extract solutions were measured according to the thiocyanate method and were compared with 1.0% BHT. The results indicate that the anti-oxidative effect of 10% S. scilloides root extract (anti-oxidative index (AOI); $72.3{\pm}4.2$) is not significantly different from that of 1.0% BHA (AOI; $76.8{\pm}3.5$) (p<0.05). However, it appears that the anti-oxidative effect of S. scilloides root extract is at least three-fold greater than that of BHA when accounting for the amount of dissolved solids in each.

• Journal of Animal Science and Technology
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• v.65 no.1
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• pp.258-270
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• 2023

Climate change has worsened droughts and floods, and created conditions more likely to lead to pathogen contamination of surface water and groundwater. Thus, there is a growing need to disinfect livestock water. Ultraviolet (UV) irradiation is widely accepted as an appropriate method for disinfecting livestock water, as it does not produce hazardous chemical compounds and kills pathogens. However, UV-based disinfection inevitably consumes electricity, so it is necessary to improve UV disinfection effectiveness. Aluminum-based reflective nanolens arrays that enhanced the effectiveness of a continuous-flow UV water disinfection system were developed using electrochemical and chemical processes, including electropolishing and two-step anodization. A continuous UV disinfection system was custom designed and the parts were produced using a three-dimensional printer. Electropolished aluminum was anodized at 40 and 80 V in 0.3 M oxalic acid, at 120 and 160 V in 1.0 M phosphoric acid, and at 200 and 240 V in 1.5 M citric acid. The average nanolens diameters (D) of the aluminum-based reflective nanolens arrays prepared using 40, 80, 120, 160, 200, and 240 V anodization were 95.44, 160.98, 226.64, 309.90, 296.32, and 339.68 nm, respectively. Simple UV reflection behind irradiated water disinfected Escherichia coli O157:H7 in water more than did the non-reflective control. UV reflection and focusing behind irradiated water using an aluminum-based reflective nanolens array disinfected E. coli O157:H7 more than did simple UV reflection. Such enhancement of the UV disinfection effectiveness was significantly effective when a nanolens array with D 226.64 nm, close to the wavelength of the irradiated UV (254 nm), was used.

• Korean Journal of Food Science and Technology
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• v.41 no.5
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• pp.578-586
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• 2009

This study was conducted to determine the effects of alkaline electrolyzed water (AIEW), acidic electrolyzed water (AcEW), 1% citric acid, and 100 ppm sodium hypochlorite, either alone or in combination with citric acid, in reducing the populations of spoilage bacteria and foodborne pathogens (Listeria monocytogenes and Escherichia coli O157:H7) on lettuce at various exposure times (3, 5, and 10 min) with different dipping temperatures (1, 20, 40, and $50^{\circ}C$). In addition, the inhibitory effect of alkaline electrolyzed water combined with citric acid on the browning reaction during storage at $4^{\circ}C$ for 15 days was investigated. Compared to the untreated control, electrolyzed water more effectively reduced the number of total bacteria, mold, and yeast than 100 ppm sodium hypochlorite under the same treatment conditions. All treatments exposed for 5 min significantly reduced the numbers of total bacteria, yeast, and mold on head lettuce. The inactivation effect of each treatment on head lettuce was enhanced as the dipping temperature increased from 1 to $50^{\circ}C$, but there was no significantly difference at temperatures greater than $40^{\circ}C$ (p<0.05). The total counts of yeast and mold in head lettuce were completely eliminated when a combination of 1% citric acid and AlEW treatment was used at temperatures greater than $40^{\circ}C$. However, decreased reduction in L. monocytogenes (2.81 log CFU/g), and E. coli O157:H7 (2.93 log CFU/g) on head lettuce was observed under these treatment conditions. In addition, enhanced anti-browning effect was observed when the samples were subjected to both 1% citric acid and AlEW treatment at temperatures greater than $40^{\circ}C$ compared to when single treatments alone were used. Thus, this combined treatment might be considered a potentially beneficial sanitizing method for improving the quality and safety of head lettuce.

• Proceedings of the KAIS Fall Conference
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• 2010.11b
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• pp.1025-1028
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• 2010

The bacteriological examination of spring water in Seogwipo-city was conducted. A total 11 spring water samples were performed from January to April, 2010. During the study period, the range of temperature was from 0.7 to $15.4^{\circ}C$, and result of the analyses showed that hydrogen ion concentrations (pH) for spring water was 0.33 to 7.8. salinity levels for sample average of 0.5 to 1.04‰, as the result of measuring dissolved oxygen (DO) for spring water showed that water dissolved oxygen were 1.02 to 7.14 mg/${\ell}$. The range of total coliform of spring water sample at 11 stations located in the designated spring water were <1.8~>1,600 MPN/100mL. And the range of geometric mean of total coliform were 1.9~117.1 MPN/100mL, The range of fecal coliform of spring water sample at 11 stations located in the designated spring water were <1.8~>1,600 MPN/100mL. And the range of geometric mean of fecal coliform were 1.8~68.1 MPN/100mL, respectively. Level of microbial contamination was examined in 11 samples for indication of bacterial contamination such as heterophic bacteria, EscherichiacoliO157;H7, salmonella spp., Vibrio parahaemolyticus, Staphylococcus aureus, Shigella spp. Were frequently detected from the spring water. Salmonella spp., S.aureus were detected in the range of $0{\sim}1.0{\times}10^1$, $0{\sim}3.0{\times}10^1$ CFU/ml, respectively. And the Escherichia coli O157;H7, Vibrio parahaemolyticus, Shigella spp. Were not detected from the examined spring water samples.

• KSBB Journal
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• v.32 no.2
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• pp.153-159
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• 2017

The purpose of this study was to investigate the probiotic properties of lactic acid bacterial strains isolated from human feces. The properties were tested on the basis of guideline for probiotic selection protocol such as tolerance for acid or bile salt, autoaggregation, antibiotic resistance, and antimicrobial activity. Total 25 lactic acid bacteria were isolated from human feces, and their antibacterial activity was tested against Staphylococcus aureus, Escherichia coli, E. coli O157:H7, Vibrio parahaemolyticus, V. alginolyticus using an agar diffusion assay. Among them, 4 selected strains were identified by analysis of their 16S rRNA, as Lactobacillus rhamnosus MG316, L. acidophilus MG501, L. reuteri MG505, and L. gasseri MG570. Results show that resistance to low pH and bile salts. Also, the selected strains were resistant to bile acid up to 3% and their autoaggregation rates were as high as 60%. All strains tested were resistance to nalidixic acid and kanamycin.

• Food Science of Animal Resources
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• v.25 no.4
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• pp.500-506
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• 2005

This study was carried out to obtain knowledges on the survival of Streptococcus mutans in the yoghurt added with green tea powder. The growth inhibition of green tea powder on the food borne pathogens and oral bacteria was measured by total microbial count, Among the tested food borne pathogens, the growth of Staphylococcus aureus and Salmonella enteritidis were not significantly affected by the addition of green tea powder, but green tea powder showed the growth inhibition effect on Escherichia coli O157:H7. The number of surviving Streptococcus mutans cell was decreased by $0.56\~0.99log$ cycle after 24 hem incubation by the addition of $0.5\~2.5\%$ green tea powder in the medium. And also the viable cell count of surviving Streptococcus mutans cells (initial inoculum $3.4\times10^7CFU/mL$) were decreased to $1.4\times10^4\~7.2\times10^4 CFU/mL$ after 48 hours incubation when $0.5\~2.5\%$ green tea powder were added to the drinkable yoghurt, Growth of Streptococcus mutans was strongly inhibited by the addition and incubation of green tea powder for 48 hum in the yoghurt.