• Korean Journal of Microbiology
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• v.51 no.1
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• pp.48-60
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• 2015

612 strains isolated from Korean traditional fermented food in Sunchang and their investigated biochemical characterization and ability of biogenic amines non-producing. We selected the SCJ4 having various activity by measurement of extracellular enzyme, antioxidant and antimicrobial activities. Selected strain SCJ4 by 16S rRNA sequencing and biochemical characterization was named Bacillus subtilis SCJ4. And then, we investigated cell growth of SCJ4, and optimized of culture medium constituents using response surface methodology as statistically method. Response surface methodology used Plackett-Burman experimental design for screening of medium constituent. Tryptone, peptone and $MgSO_4$ as medium constituent improving cell growth selected. In order to find out optimal concentration on each constituent, we carried out central composite design. Consequently, optimized concentrations of tryptone, peptone and $MgSO_4$ were predicted to be 15.35 g/L, 12.235 g/L, and 3.5 g/L respectively. Through the model verification, we confirmed about 1.28-fold improvement of the dried cell weight from 0.8767 g/L to 1.1222 g/L when compared to basal medium.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.1
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• pp.18-27
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• 2020

The correct distinction of carbapenem-resistant Enterobacteriaceae (CRE) and ccarbapenemase producing Enterobacteriaceae (CPE) and the rapid detection of CPE are important for instituting the correct treatment and management of clinical infections. Screening protocols are mainly based on cultures of rectal swab specimens on selective media followed by phenotypic tests to confirm a carbapenem-hydrolyzing activity, the rapid carbapenem inactivation method, lateral flow immunoassay, the matrix-assisted laser desorption ionization-time-of-flight test and molecular methods. The CPE is accurate for detection, and is essential for the clinical treatment and prevention of infections. A variety of phenotypic methods and gene-based methods are available for the rapid detection of carbapenemases, and these are expected to be routinely used in clinical microbiology laboratories. Therefore, to control the spread of carbapenemase, many laboratories around the world will need to use reliable, fast, high efficiency, simple and low cost methods. Optimal effects in patient applications would require rapid testing of CRE to provide reproducible support for antimicrobial management interventions or the treatment by various types of clinicians. For the optimal test method, it is necessary to combine complementary test methods to discriminate between various resistant bacterial species and to discover the genetic diversity of various types of carbapenemase for arriving at the best infection control strategy.

• Journal of Life Science
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• v.21 no.9
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• pp.1244-1250
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• 2011

The study was performed to evaluate the antibacterial and antiviral activities of ginseng fine root in order to search for antibacterial substances. Among 8 kinds of fermentation strains, Lactobacillus plantarum was selected based on viable cell count and antibacterial activities during incubation. Optimum conditions of ginseng fine root fermentation for L. plantarum were incubation at $35^{\circ}C$ for 48 hr in 5% ginseng fine root broth. That methanolic extract of fermented ginseng fine root broth was observed to be antibacterial and have antiviral activities. The results of paper disc method of non-fermented extract and fermented extract measured against E. coli was 11 mm and 20 mm, S. aureus was 15 mm and 22 mm, respectively. Shaking flask method was observed to inhibit the growth E. coli and S. aureus in fermented extract by 99.9%. However, antiviral activity of Feline calicivirus (FCV) was mostly activated. Fermented extract was used to investigate the compositional changes of ginsenosides on HPLC analysis. By fermentation, ginsenoside Rg1, Re and Rd were increased, with Rd showing a significant increase of 50 ${\mu}g/g$. These results suggest that ginseng fine root extract is a useful resource.

• Journal of Life Science
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• v.29 no.6
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• pp.697-704
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• 2019

This study performed to investigate the probiotic properties of lactic acid bacteria 200 strains isolated from traditional fermented foods. Based on being higher tolerance to bile salts and showing higher acid resistance, 4 LAB Strains were selected in the screening experiment; Lactobacillus plantarum SRCM 102224, Lb. plantarum SRCM102227, Lb. paracasei SRCM102329, Lb. paracasei SRCM102343. Antibacterial activity against various pathogens, acid and bile salt tolerance, hemolytic phenomenon, cell surface hydrophobicity, and antibiotic resistance were examined. Among the tested strains, SRCM 102343 (95.9%) was highly observed hydrophobicity compared to Lb. rhmanosus GG (13.4%) as control. In this study, the in vitro adhesion properties of 4 strains of LAB was investigated using human intestinal caco-2 cell cultures. SRCM102329 and SRCM102343showed higher adherence to caco-2 cells than Lb. rhamnosus GG. The antibacterial activities of 4 strains LAB were investigated. the 3 strains showing strongly antimicrobial activity against Escherichia coli ATCC10798, Staphylococcus aureus KCCM11593, Listeria invanovii KCTC3444, Bacillus cereus ATCC11778 and S. enterica serovar. Typhi KCTC1926. These results suggest that selected strains have good probiotic potential for application in functional foods.

• Korean Journal of Food Science and Technology
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• v.52 no.6
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• pp.670-677
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• 2020

To prevent contamination by Campylobacter jejuni during chicken carcass processing, the effect of emulsifiers on C. jejuni inoculated on chicken skin was investigated using confocal laser scanning microscopy. Among the 8 emulsifiers (SWA-10D, L-7D, M-7D, S-1670, L-1695, P-1670, polysorbate 20, polysorbate 80) tested for antimicrobial activity by the paper disk method, 4 emulsifiers (L-7D, L-1695, polysorbate 20, polysorbate 80) were screened further. Emulsifier L-1695 showed the largest clear zone at a concentration of 200 mg/mL. The 4 emulsifiers subjected to primary screening were screened for heat and pH stability. In the contact surface test, emulsifier L-1695 showed the lowest log CFU/㎠ value on both stainless steel and ceramic surfaces. When emulsifier L-1695 was applied via general and electrostatic spray methods, the number of C. jejuni entrapped inside chicken skin follicles was significantly reduced in both methods. In conclusion, the emulsifier L-1695 could be employed as a microbial detachment agent in the chicken carcass processing industry.

• Korean Journal of Food Science and Technology
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• v.41 no.6
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• pp.673-680
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• 2009

This study was conducted to screen for plant food materials that improve human intestinal microflora, especially microorganisms associated with obesity. Among 30 tested plant food materials, the extract of Schizandra chinensis inactivated Eubacterium limosum, Bacteroides fragilis and Clostridium spp. Additionally, S. chinensis extract was also found to have a growth-promoting effect on Bifidobacterium spp.. The antimicrobial activity and antioxidant activity of the water extract did not decrease in respond to heating. Additionally, the water extract of S. chinensis did not show a toxic effect on the growth of Caco-2 cells. In vivo feeding tests were performed to investigate the influence of extract on the intestinal microflora in rats. Although the extract did not reduce obesity induced by a high fat diet, it led to significant increase in the population of Bifidobacterium spp. and a decrease in the population of Clostridium spp. in rats. Taken together, these results indicate that S. chinensis could be useful as a functional food component to control intestinal microbial flora.