• Microbiology and Biotechnology Letters
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• v.25 no.5
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• pp.442-447
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• 1997

To development food preservative, antimicrobial activities of Schizandra chinensis (SC) against Listeria monocytogenes Scott A, L. monocytogenes Brie I and L. monocytogenes ATCC 19111 were investigated. The growth of L. monocytogenes Scott A, L. monocytogenes Brie I and L. monocytogenes ATCC 19111 was inhibited apparently in Tryptic Soy Broth (TSB) containing 1% SC at 35$\circ$C and it was found that these had antibacterial effects against a broad spectrum of pathogenic bacteria such as S. aureus ATCC 29737, B. subtilis KCTC 1021, E. coli ATCC 11775. The growth of L. monocytogenes was also inhibited about 3 to 5 log$_{10}$ cycle by 0.1% of three fractions of the alcohol extract such as ether, ethyl acetate and butanol. Acidic, weakly acid and neutral fraction of ether fraction showed inhibitory properties against L. monocytogenes.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.615-622
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• 2013

The purpose of this study was to evaluate microbial contamination of melons in Korea. A total of 123 samples including melon fruits, leaves, seeds, soils, and irrigation water were collected from farms and markets to detect total aerobic bacteria, coliform, Escherichia coli, and pathogenic bacteria such as Bacillus cereus, Listeria monocytogenes, Salmonella spp., and Staphylococcus aureus. Samples were collected from Iksan and Nonsan farms to monitor bacterial levels on pre-market melons. The total aerobic and coliform bacteria on melon cultivation were between 0.43 and 6.65 log CFU $g^{-1}$, and 0.67 and 2.91 log CFU $g^{-1}$, respectively. Bacillus cereus, a fecal coliform, was detected in soils and melon leaves from Iksan farm at 2.95, 0.73 log CFU $g^{-1}$, respectively, and in soils from Nonsan farm at 3.16 log CFU $g^{-1}$. Market melon samples were collected to assay bacterial load on melon being sold to consumers. The contamination levels of total aerobic bacteria in agricultural markets, big-box retailers, and traditional markets were 4.82, 3.94, 3.99 log CFU $g^{-1}$, respectively. The numbers of coliform in melon on the markets ranged from 0.09 to 0.49 log CFU $g^{-1}$. Listeria monocytogenes, Salmonella spp., and Staphylococcus aureus were not detected in any samples. The count of total aerobic bacteria on melon seeds ranged from 0.33 to 3.34 log CFU $g^{-1}$. This study found that irrigation water, soil, manure and various farm work activities including post-harvest processes were latent sources of microbial contamination. These results suggest that hygienic management and monitoring of soil, water, and agricultural material should be performed to reduce microbial contamination in melon production.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.1
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• pp.35-41
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• 2003

The study was conducted to develope a rapid method for the detection of Yersinia enterocolitica in spring water and vegetables via multiplex polymerase chain reaction (PCR) technique using ail, yst, uirF and subgenus-specific Y16S primers. Specificity and sensitivity of multiplex PCR and application of best primers for the detection of Y. enterocolitica from spring water and vegetables were investigeted. Y. enterocolitica ATCC 27729 strains gave 356 bP and 200 bp (Y16S) and 134 bp (yst) bands. but Y. enterocolitica ATCC 9610 and ATCC 23715 strains gave 200 bp and 134 bp bands.In the meanwhile, non-pathogenic Yersinia species, such as Y. frederikseni, Y. inter-media, Y. kristenseni and Y. pseudotuberculosis gave only single 200 bp band, and other bacteria including Escherichia coli O157:H7 ATCC 25392, Shigella dysenteri. Staphylococcu aureus ATCC 25923 and Listeria mo-nocytogenes ATCC 19111 did not show any bands. Among primers, yst and Y16S primer showed the best sensitivity. Seven CFU/mL Y. enterocolitica cells could be detected with yst and Y16S primers and the sensitivity was significantly improved by the further 2nd PCR after 38 cycles of first PCR amplication. Spring water, cabbage and mushroom were inoculated with Y. enterocolitica to determine the sensitivity of multiplex-PCR for the rapid detection of Y. enterocolitica. Multiplex-PCR assay could detect 7 or 70 cells in spring water and vegetables using whole cell lysate with repeating PCR amplication.