• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.2
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• pp.239-247
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• 2015

This experiment was conducted to obtain the have higher contents of pharmaceutical constituents as well as higher yield from colchicine induced diploid and tetraploid extracts of Platycodon grandiflorum. In order to determine the biological activity, this study was focused to evaluate the cytotoxicity, antimicrobial on the bronthus disease bacteria, antioxidant enzyme activity of diploid and tetraploid extracts in P. grandiflorum. The activities of antioxidant enzyme according to different solvent extracts were measured as superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX). The cytotoxicity of methanol extracts of P. grandiflorum showed significant differences between tetraploid and diploid. That is, the cytotoxic effect against human cancer cell was higher in tetraploid than in diploid. At all extracts concentration, tetraploid samples showed high toxicity and the $IC_{50}$ (concentration causing 50% cell death) value showed the highest on HCT-116 cell ($105.91{\mu}g/mL$), and exhibited significant activity against the Hep 3B cell ($140.67{\mu}g/mL$), SNU-1066 cell ($154.01{\mu}g/mL$), Hela cell ($158.37{\mu}g/mL$), SNU-601 cell ($182.67{\mu}g/mL$), Calu-6 cell ($190.42{\mu}g/mL$), MCF-7 cell ($510.19{\mu}g/mL$). Antimicrobial activities of diploid P. grandiflorum were relatively low compared to tetraploid P. grandiflorum on most of the bacterial strains. In tetraploid P. grandiflorum, K. pneumoniae showed the clear zone formation (18~19 mm) of growth inhibition, followed by the clear zone formation of 13~15 mm on C. diphtheria and S. pyogenes. The antimicrobial activities in diploid P. grandiflorum were the highest on K. pneumonia (14~15 mm), and showed the clear zone formation of 11~12 mm on C. diphtheria and 12~13 mm on S. pyogenes. The antimicrobial activity is thought to look different depending on the bacterial strains and the polyploidy of P. grandiflorum. The root extract of P. grandiflorum had the highest (97.2%) SOD enzyme activity in ethyl acetate partition layer of tetraploid while water partition layer of diploid showed the lowest (48.6%) SOD enzyme activity. The activity of CAT showed higher values in the root of tetraploid than in the diploid of P. grandiflorum in all partition layers except butyl alcohol. The activities of APX and POD showed higher values in the root of tetraploid than in the diploid of P. grandiflorum in all fraction solvents except water layer. These results indicate that the tetraploid P. grandiflorum can be used as a source for developing cytotoxic agent and antimicrobials which can act against bronchus diseases bacterial strains.

• Journal of dental hygiene science
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• v.12 no.2
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• pp.155-162
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• 2012

Somok, the heart wood of Caesalpinia sappan is used in traditional Chinese medicine. Adherence of S. mutans to the tooth surface can result in the formation of a dental plaque. This study was performed to investigate the antibacterial activity and bacterial adhesion of ethyl acetate extract from C. sappan against S. mutans ATCC 25175. The bacteria were cultured in brain heart infusion(BHI) broth, and then incubated under 5% $CO_2$ at $37^{\circ}C$ for 18~24 hours. The antimicrobial activity of the ethyl acetate extract of C. sappan was then examined using the paper disc methods and MIC. In addition, bacterial adherence to hydroxyapatite was also examined. The ethyl acetate extract was shown to produce inhibitory effects and had MIC values of 125 mg/ml against S. mutans ATCC 25175. The ethyl acetate extract inhibited adhesion of S. mutans to saliva coated-hydroxyapatite beads(S-HA). At 24 hr, the ethyl acetate extract significantly reduced the adherence of S. mutans to S-HA beads relative to the control. The isolated active substance was identified as brazilin($C_{16}H_{14}O_5$) by $^1H-NMR$ and $^{13}C-NMR$. Thus, the application of C. sappan can be considered a useful and practical method for the prevention of dental caries.

• Journal of Microbiology and Biotechnology
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• v.27 no.10
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• pp.1763-1772
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• 2017

This study aimed to isolate and characterize antibacterial metabolites from Pharbitis nil seeds and investigate their antibacterial activity against various plant pathogenic bacteria. The methanol extract of P. nil seeds showed the strongest activity against Xanthomonas arboricola pv. pruni (Xap) with a minimum inhibition concentration (MIC) value of $250{\mu}g/ml$. Among the three solvent layers obtained from the methanol extract of P. nil seeds, only the butanol layer displayed the activity with an MIC value of $125{\mu}g/ml$ against Xap. An antibacterial fraction was obtained from P. nil seeds by repeated column chromatography and identified as pharbitin, a crude resin glycoside, by instrumental analysis. The antibacterial activity of pharbitin was tested in vitro against 14 phytopathogenic bacteria, and it was found to inhibit Ralstonia solanacearum and four Xanthomonas species. The minimum inhibitory concentration values against the five bacteria were $125-500{\mu}g/ml$ for the n-butanol layer and $31.25-125{\mu}g/ml$ for pharbitin. In a detached peach leaf assay, it effectively suppressed the development of bacterial leaf spot, with a control value of 87.5% at $500{\mu}g/ml$. In addition, pharbitin strongly reduced the development of bacterial wilt on tomato seedlings by 97.4% at $250{\mu}g/ml$, 7 days after inoculation. These findings suggest that the crude extract of P. nil seeds can be used as an alternative biopesticide for the control of plant diseases caused by R. solanacearum and Xanthomonas spp. This is the first report on the antibacterial activity of pharbitin against phytopathogenic bacteria.

• Korean Journal of Microbiology
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• v.46 no.1
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• pp.73-79
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• 2010

The Korea Polar Research Institute (KOPRI) has assembled a culture collection of cold-adapted bacterial strains from both the Arctic and Antarctic. To identify excellent protease-producers among the proteolytic bacterial collection (874 strains), 78 strains were selected in advance according to their relative activities and were subsequently re-examined for their extracellular protease activity on $0.1{\times}$ ZoBell plates supplemented with 1% skim milk at various temperatures. This rapid and direct screening method permitted the selection of a small group of 15 cold-adapted bacterial strains, belonging to either the genus Pseudoalteromonas (13 strains) or Flavobacterium (2 strains), that showed proteolytic activities at temperatures ranging between $5-15^{\circ}C$. The cold-active proteases from these strains were classified into four categories (serine protease, aspartic protease, cysteine protease, and metalloprotease) according to the extent of enzymatic inhibition by a class-specific protease inhibitor. Since highly active and/or cold-adapted proteases have the potential for industrial or commercial enzyme development, the protease-producing bacteria selected in this work will be studied as a valuable natural source of new proteases. Our results also highlight the relevance of the Antarctic for the isolation of protease-producing bacteria active at low temperatures.

• The Korean Journal of Mycology
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• v.41 no.2
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• pp.112-117
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• 2013

Phytophthora capsici is one of major limiting factors in production of pepper and other important crops worldwide by causing foliage blight and rot on fruit and root. Increased demand for the replacement of fungicides has led to searching a promising strategy to control the fungal diseases. To meet eco-friendly agriculture practice, we isolated microorganisms and assessed their beneficial effects on plant health and disease control efficacy. A total of 360 bacterial strains were isolated from rhizosphere soil of healthy pepper plants, and categorized to 5 representative isolates based on colony morphology. Among the 5 bacterial strains (GJ-1, GJ-4, GJ-5, GJ-11, GJ-12), three bacterial strains (GJ-1, GJ-11, GJ-12) presented antifungal activity against P. capsici in an fungal inhibition assay. In phosphate solubilization and siderophore production, the strain GJ-1 was more effective than others. The strain GJ-1 was identified as Bacillus sp. using 16S rDNA analysis. Bacillus sp. GJ-1 was also found to be effective in inhibiting other plant pathogenic fungi, including Rhizoctonia solani, Pythium ultimum and Fusarium solani. Therefore, the Bacillus sp. GJ-1 can serve as a biological control agent against fungal plant pathogens.

• Korean Journal of Veterinary Research
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• v.47 no.4
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• pp.449-456
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• 2007

The approval of use of certain food-grade phosphates as food additives in a wide variety of meat products greatly stimulated research on the applications of phosphates in foods. Although phosphates have never been classified as antimicrobial agents, a number of investigators have reported that phosphates have antimicrobial activities. Phytic acid is a natural plant inositol hexaphosphate constituting 1-5% of most cereals, nuts, legumes, oil seeds, pollen, and spores. In this study, we investigated antibacterial activities of sodium phytate (SPT), sodium pyrophosphate (SPP), sodium tripolyphosphate (STPP) on Salmonella typhimurium in tryptic soy broth and in row meat media including chicken, pork and beef. SPY, SPP and STPP at the concentrations of 0.5 and 1% dose-dependently inhibited the growth of S. typhimurium in tryptic soy broth at various pHs. The antibacterial activities of SPT and STPP were the stronger than that of SPP. In chicken, pork, and beef, SPT, SPP and STPP at the concentrations of 0.1, 0.5 and 1.0% significantly inhibited the bacterial growth in a dose-dependant manner (p < 0.05). The antibacterial activities of SPT, SPP, and STPP were more effective in chicken than beef. SPT and STPP at the concentration of 1% reduced the bacterial count by about 2 log units. The addition of SPT, SPP and STPP at the concentration of 0.5% in meats increased the meat pHs by 0.28-0.48 units in chicken, pork, and beef. These results suggest that SPT and STPP were equally effective for the inhibition of bacterial growth both in TSB and meat media and that SPT can be used as an animal food additive for increasing shelf-life and functions of meats.

• Journal of Life Science
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• v.26 no.2
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• pp.265-274
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• 2016

Toxin-antitoxin (TA) systems are ubiquitous genetic modules that are evolutionally conserved in bacteria and archaea. TA systems composed of an intracellular toxin and its antidote (antitoxin) are currently classified into five types. Commonly, activation of toxins under stress conditions inhibits diverse cellular processes and consequently induces cell death or reversible growth inhibition. These effects of toxins play various physiological roles in such as regulation of gene expression, growth control (stress response), programmed cell arrest, persister cells, programmed cell death, phage protection, stabilization of mobile genetic elements or postsegregational killing of plasmid-free cells. Accordingly, bacterial TA systems are commonly considered as stress-responsive genetic modules. However, molecule screening for activation of toxin in TA system is available as development of antimicrobial agents. In addition, cytotoxic effect induced by toxin is used as effective cloning method with antitoxic effect of antitoxin; consequently cells containing cloning vector inserted a target gene can survive and false-positive transformants are removed. Also, TA system is applicable to efficient single protein production in biotechnology industry because toxins that are site-specific ribonuclease inhibit protein synthesis except for target protein. Furthermore, some TA systems that induce apoptosis in eukaryotic cells such as cancer cells or virus-infected cells would have a wide range of applications in eukaryotes, and it will lead to new ways of treating human disease. In this review, we summarize the current knowledge on bacterial TA systems and their applications.

• Journal of Life Science
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• v.21 no.3
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• pp.393-399
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• 2011

The mast cell is one of the major effector cells in inflammatory reactions and can be found in most tissues throughout the body. Activated mast cells can produce histamine, as well as a wide variety of other inflammatory mediators such as eicosanoids, proteoglycans, proteases, and several pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-${\alpha}$, and interleukins (IL-6), IL-8, IL-4, IL-13. In the present study, we isolated two bacterial strains (J80 and G147) from fermented soybean and Jeotgal, and investigated the inhibitory effects of their extracts which were prepared by several pretreatment methods (sonication for 20 min, heating at $100^{\circ}C$ for 30 min, autoclaving at $121^{\circ}C$ for 15 min) on the mast cell-mediated inflammatory response. The pretreated bacterial extracts had no cytotoxicity against Human Mast Cell (HMC-1). Among various pretreatments, the extracts treated at $100^{\circ}C$ showed highest inhibition of histamine release (J80, 28.46%; G147, 41.14%). The J80 and G147 extracts treated at $100^{\circ}C$ resulted in the inhibition of IL-6 secretion by 38.46% and 56.45%, respectively. The J80 extract treated at $100^{\circ}C$ resulted in the inhibition of TNF-${\alpha}$ secretion by 66.67%, but G147 extract showed the highest inhibition effect by 41.1% when treated with sonication. These results suggest that bacterial extracts treated at $100^{\circ}C$ have a higher level of anti-inflammatory effects than other treatments such as sonication or autoclaving.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.792-798
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• 2006

The probiotic characteristics of a total of 137 lactic acid bacterial strains isolated from soybean paste were investigated. Among those tested, the D37 strain was selected as a probiotic bacteria due to its acid and bile tolerance, and its strong anti-cancer and antibacterial activities. The D37 strain showed highly stable viability at acidic pH for 2 hr, and was very stable in 10% bovine bile. The viability of human colon cancer HT-29 cells was inhibited more than 60% at a $200\;{\mu}/mL$ concentration of D37 cell-free culture supernatant, and the degree of inhibition was concentration-dependent. The D37 strain showed a wide range of antibacterial activities against food-borne pathogenic bacteria such as Escherichia coli O157, Listeria spp., Vibrio spp., Salmonella spp., and Staphylococcus aureus. According to phenotypic characteristics and the utilization of various sugars, the D37 strain was identified as Lactobacillus cellobiosus.

• Journal of Applied Biological Chemistry
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• v.57 no.3
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• pp.279-286
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• 2014

The purpose of this study was to evaluate the biological activities of extracts of ramie (Boehmeria nivea (L.) Gaud.), hereafter referred to as Bn. Bn extracts from various collecting area were extracted with methanol. Two extracts from our study, Bn-13 and -82, showed significant antioxidant properties, likely due to their ability to scavenge free radicals. In addition, Bn extracts showed stronger anti-bacterial activity against Escherichia coli (Bn-40), Stapylococcus aureus (Bn-33), and Helicobacter pylori (Bn-05). In addition, this study was conducted to evaluate the anti-inflammatory effects of Bn extracts in lipopolyssacharide (LPS)- and interferon-${\gamma}$ (IFN-${\gamma}$)-stimulated RAW 264.7 macrophages cells. Bn-37 significantly inhibited the production LPS/IFN-${\gamma}$-induced nitric oxide. The most noteworthy anti-cancer effect was found in Bn-23. Bn-08 showed inhibition of aldose reductase. This study provides basic information for the development of functional foods.