• Journal of Food Hygiene and Safety
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• v.22 no.2
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• pp.77-81
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• 2007

Antimicrobial activity of both fresh Prunus mume and Prunus mume liqueur byproduct (PLB), generated after producing Prunus mume liqueur were examined against various pathogeinc bacteria such as Listeria monocytogenes Scott A, Listeria monocytogenes ATCC 19115, Bacillus cereus KCCM 11341, Staphylococcus aureus KCCM 12255, Pseudomonas fluorescens ATCC 21541, Escherichia coli O157:H7, Salmonella Typhimurium ATCC 14028, and Shigella sonnei. PLB showed strong antibacterial effects against tested pathogenic bacteria.L. monocytogenes ATCC 19115, B. cereus KCCM 11341, S. sonnei, and E. coli O157:H7 were not detected in trytpic soy broth containing 1% of prunus mume or PLB after 24-hour incubation at $37^{\circ}C$, respectively. Prunus mume showed higher antimicrobial activities than that of PLB against tested pathogens.

• Journal of the Korean Geotechnical Society
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• v.18 no.1
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• pp.133-140
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• 2002

Phosphogypsum is a by-product from the phosphoric acid process for manufacturing fertilizers. It consists mainly of $(CaSO_4.2H_2O)$ and contains some impurities such as$(P_2O_5)$, 불소$(F_-)$, and organic substances. The annual world production of this material is up to 150 million tons and is up to 1.57 million tons in Korea. Therefore studies describe application of phosphogypsum to daily and middle cover materials in landfill. For this Purpose, experiments were performed to evaluate the engineering properties of the material by sieve analysis, specific gravity, consistency of soil, compaction, CBR, permeability, mi environmental characteristics of leaching test, reactor test. The results of this study are as follows : The mixing and layer conditions of CBR value are 6.2~6.3%, coefficient of permeability is $\alpha$$\times10_{-5}~10_{-6}cm/sec$. And leaching test results are far below than those of regulatory requirement of Waste Management Act, Soil Environment Preservation Act in Korea and RCRA in USA. Therefore phosphogypsum can be used as daily and intermediate cover materials in landfill.

• Journal of Microbiology and Biotechnology
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• v.16 no.8
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• pp.1229-1235
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• 2006

A lab-on-a-chip (LoC) was designed for simultaneous monitoring of microorganisms, antibiotic residues, somatic cells, and pH in raw milk. The LoC was fabricated from polydimethylsiloxane (PDMS) using microelectromechanical system (MEMS) technology, which consisted of two parts; a protein array and microchannel. The protein array was fabricated by immobilizing five types of antibodies corresponding to two microorganisms, two antibiotic residues, and somatic cells. A sol-gel film was deposited on a glass substrate to immobilize the antibodies. The target analytes in raw milk could be bound with the corresponding antibody by an immunoreaction, and the antigen-antibody complex was detected using fluorescence microscopy. SNARF-dextran was used as a pH indicator, and the SNARF-entrapped hydrogel was attached to the microchannel in the chip. After injecting the milk sample into the channel, the pH was measured by monitoring the change in fluorescence intensity by fluorescence microscopy. The on-chip simultaneous assay of two microorganisms (E. coli O157:H7 and Streptococcus agalactiae), two antibiotic residues (penicillin G and dihydrostreptomycin), and neutrophils was successfully accomplished using the proposed LoC system.

• Korean Journal of Veterinary Service
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• v.22 no.4
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• pp.411-418
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• 1999

In this studies, the ability of chlorine and lactic acid to reduce bacterial population of the pathogenic microorganisms were examined on artificially inoculated chicken skin. About 10$^{5}$ cells of staphylococcus aureus, salmonella enteritidis, listeria monocytogenes and escherichia coli O157:H7 were inoculated in chicken skin. The contaminated samples were washed for 1 min with sodium hypochlorite solutions that contained 2, 5, 10, 20 and 50mg/$\ell$ available chlorine and counted number of the agents. Viable population were no significantly difference (p$\geq$0.05) between concentration of chlorine and strains of the pathogens. In the samples inoculated with pathogens were washed in 20mg/$\ell$ chlorine and then stored at $^5{\circ}C$ for up to 10 days, the initial counts of psychrotrophs and aerobic plate counts were 4.02 to 4.36 log cfu/$\textrm{cm}^2$ and increased slightly in course of time. But 10 days after, the pathogens were a little reduced from 3.66~4.91 log cfu/$\textrm{cm}^2$ to 2.54~4.66 log cfu/$\textrm{cm}^2$. In the case of washed skin with solution of 20mg/$\ell$ chlorine and 0.5% lactic acid then store at $^5{\circ}C$ for up to 10 days, population of psychrotrophs and aerobic plate counts on chicken skin were markedly reduced immediately after treatment, but the numbers of contaminants were slightly increased after 6 and 8 days. Specifically, numbers of St aureus, S enteritidis, L monocytogenes and E coli O157:H7 were reduced to 0.5, 0.4, 0.3 and 1.15 log cfu/$\textrm{cm}^2$ after 10 days of storage, respectively, on aerobic plate counts.

• 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.

• Korean Journal of Food Science and Technology
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• v.41 no.4
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• pp.452-457
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• 2009

In order to secure microbiological safety and quality of commercial vegetable sprouts, buckwheat seeds and sprouts were investigated for their microbiological flora and for the effect of chlorine treatment on quality. Microbiological analyses showed that major inherent bacteria including Enterobacter, Sphingomonas, and Klebsiella were found in commercial buckwheat sprouts with a population size ranging from $10^5$ to $10^7$ CFU/g. In addition, buckwheat seeds had a similar microbial flora to sprouts. Foodborne pathogenic bacteria such as Escherichia coli O157:H7, Staphylococcus aureus, Salmonella Typhimurium, and Listeria monocytogenes were not detected in the sprout or in the seed samples. Chlorine treatment with 50-150 ppm sodium hypochlorite noticeably reduced viable bacteria cell counts of the sprouts by about 1 log. However, no significant difference was observed among the different chlorine concentrations. After storage for 7 days at $5^{\circ}C$, the sprouts treated with 100-150 ppm chlorine showed higher sensory scores in visual quality than the others (p<0.05). The results indicated that proper pretreatment, such as dipping in chlorinated water, could confer a beneficial effect on the microbiological safety and visual quality of buckwheat sprouts.

• 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 Dairy Science and Biotechnology
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• v.39 no.3
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• pp.121-127
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• 2021

Yogurt is produced by bacterial fermentation of milk and contains lactic acid bacteria (LAB), which produce various metabolites such as organic acid, hydrogen peroxide, and bacteriocin. This study aimed to investigate cell-free supernatants (CFS) of LAB isolated from Tibetan yogurt. CFS (TY1, TY2, TY3, TY4, TY5, TY6, and TY7) from selected strains of LAB were co-incubated with four different foodborne pathogenic bacteria, namely E. coli O157:H7, Listeria monocytogenes, Salmonella typhimurium, and Staphylococcus aureus. Inhibition of foodborne pathogenic bacterial growth was not affected in the presence of CFS (pH 6.5). In contrast, CFS without neutralization completely inhibited the growth of the bacteria. Furthermore, when the concentration of CFS (without neutralization) was changed to 1:4 and 1:8, a difference in inhibition was observed between Gram-positive and Gram-negative bacteria. CFS more effectively inhibited the growth of Gram-negative E. coli O157:H7 and S. Typhimurium than Gram-positive L. monocytogenes and S. aureus. These results suggest that organic acids in LAB may inhibit the growth of foodborne pathogenic bacteria, particularly Gram-negative bacteria.

• Journal of Life Science
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• v.20 no.12
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• pp.1882-1888
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• 2010

To develop probiotics, a kind of Lactobacillus sp. was isolated from infant feces. The bacterium was identified as Lactobacillus rhamnosus through 16S rDNA sequence analysis. The strain was a facultative anaerobe which grew better in aerobic conditions. The bacterium lowered the pH of the culture solution down to 2.4 during 48 hr in the MRS medium. The strain inhibited the growth of 6 pathogens - S. aureus, L. monocytogens, S. typhimurium, E. coli O-157, V. parahaemolyticus and P. aeruginosa. When the Lactobacillus were fed to chickens, along with commercial feed, for one month, amounts of $H_2S$ and $NH_3$ in the feces of the chicken decreased to 50% and 70%, respectively, compared to those of control group chickens. Amounts of other bad smells such as $(CH_3)SH$, $(CH_3)_2S$ and $(CH_3)_2S_2$ were not much different in the Lactobacillus-fed chickens compared to the control group. On the other hand, egg weights of the chickens fed Lactobacillus were higher by about $5{\pm}1\;g$ than those in the control group.

• Journal of Food Hygiene and Safety
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• v.31 no.6
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• pp.406-413
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• 2016

This study was performed to evaluate and establish a sample preparation method for the detection of food-borne pathogens in animal origin foods. Ham, yogurt, and Korean beef inoculated with Escherichia coli O157:H7, Staphylococcus aureus, and Salmonella Typhimurium, were tested for the effects of diluent composition, processing time, and proportion of diluent to sample. The diluents used were peptone water (PW), Saline solution (SS), Butterfield's phosphate buffered dilution water (BPD), and Buffered peptone water (BPW). The processing time periods considered for the samples were 30, 60, 90, 120, and 300 sec, and the proportions of diluent to samples tested were 1:2, 1:4, 1:9, and 1:19. Yogurt and beef showed the highest number of bacteria when treated with BPW (p < 0.05). However, ham showed no significant difference between the treatments with four different diluents. Optimum proportions of diluent to ham, yogurt, and beef were 1:9, 1:2, and 1:4, respectively. The processing time of 120 sec was chosen as optimum, because it showed the best recovery rate in all sample types. In this manner, detection of food-borne bacteria with the selected optimal conditions was indicated by a recovery rate of more than 85%. These data suggest that an appropriate diluent composition and diluent volume should be used depending on the type of sample, which would thereby increase the accuracy of detecting food-borne bacteria in animal origin foods.