• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.605-614
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• 2022

In this study, oregano was extracted by supercritical extraction and hydrothermal extraction method. In vitro experiments such as antimicrobial and antioxidant activity test were performed. As a result of the disc diffusion method, only the supercritical extracts formed a clear zone. The MIC for S. aureus was found only in the supercritical fluid extracts and it was 1000 ㎍/mL. The hydrothermal extract's MIC is 125 ㎍/mL for C. acnes. Through biofilm inhibition assay, we found that the supercritical fluid oregano extracts inhibit the biofilm of S. aureus by more than 70% even at low concentrations of 125 ㎍/mL. On the other hand, the antioxidant ability of the hydrothermal extract was better than that of the supercritical fluid extracts. Furthermore, we tried to make a skincare ingredient for atopic dermatitis by utilizing the S. aureus biofilm inhibitory ability of oregano supercritical fluid extracts. Liposome was used to overcome the low solubility of the oregano supercritical fluid extracts and increase stability.

• Journal of Pharmacopuncture
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• v.10 no.3
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• pp.47-52
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• 2007

Objective This experimental study was performed to investigate the effect of Coptidis rhizoma extract compared with quantity on Staphylococcus aureus that induce keratitis. Methods Minimal inhibitory concentration(MIC) was measured by dropping to $50{\mu}l$　according to density Coptidis rhizoma extract(100%, 10%, 1%, 0.1%) compared with quantity(40g, 80g, 160g). Anti-bacterial potency was measured by the size of inhibition zone with change of volume. Results 1. MIC on Staphylococcus aureus in Coptidis rhizoma extract was showed anti-bacterial potency compared with quantity and density in 100% and 10% of all samples(40g, 80g, 160g). 2. MIC on Staphylococcus aureus in Coptidis rhizoma extract(40g, 80g, 160g) was showed anti-bacterial potency compared with quantity all samples($20{\mu}l,\;30{\mu}l,\;40{\mu}l,\;50{\mu}l$) in 100% density. 3. MIC on Staphylococcus aureus in Coptidis rhizoma extract(40g, 80g, 160g) was showed anti-bacterial potency compared with quantity all samples ($20{\mu}l,\;30{\mu}l,\;40{\mu}l,\;50{\mu}l$) in 100% density. Anti-bacterial potency of 80g Coptidis rhizoma extract decreased compared with 40g. Anti-bacterial potency of 160g Coptidis rhizoma extract decreased compared with 40g in $20{\mu}l,\;30{\mu}l$. Conclusions Coptidis rhizoma extract was showed anti-bacterial potency compare with quantity and density. In herbal drug, antibacterial potency compare with quantity and density must be studied.

• The Korean Journal of Mycology
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• v.20 no.3
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• pp.259-268
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• 1992

Fifty-three actinomycetes antagonistic to Phytophthora capsici and Magnaporthe grisea were isolated from rhizosphere soils in six pepper-growing areas and ashore soils. Thirty-two antagonistic actinomycetes, showing inhibition zone larger than 5 mm, were classified into 20 groups according to their colony morphology and color. The antagonistic activity against P. capsici greatly varied, which showed inhibition zone sizes in the ranges from 5.7 to 17.5 mm on V-8 juice agar and from 2.5 to 17 mm on tryptic soy agar. The antagonistic activity of some actinomycetes tested was remarkably different between the two test media. The antagonists showed a relatively broad antifungal spectrum, but their antibacterial activity was negligible, except for Pseudomonas solanacearum. Butanol extracts of culture filtrates from antagonistic actinomycetes inhibited mycelial growth of P. capsici and M. grisea, thereby confirming strongly antibiotic production in culture. Culture filtrates of some antagonistic actinomycetes completely inhibited Phytophthora blight in pepper plants.

• Journal of Integrative Natural Science
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• v.7 no.3
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• pp.173-182
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• 2014

To simplify the different biological investigation of the methanolic extract and solvent-solvent partitioning of Lablab purpures (L. purpures) bark. In-vitro anti-oxidant study was determined using total DPPH radical scavenging assay. In vitro antimicrobial study was measured by observing zone of inhibition. The cytotoxic activity was studied using brine shrimp lethality bioassay and thrombolytic activity by clot disruption method. The antioxidant potential was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and Folin-Ciocalteau reagents using butylated hydroxytolune (BHT) and ascorbic acid as standards. The Aqueous soluble fraction revealed the highest free radical scavenging activity ($IC_{50}=48.76{\mu}g/mL$). The antimicrobial screening of the bark of L. purpures exhibited mild to moderate activity in test microorganisms. The CSF showed the maximum relative percentage inhibition against Salmonella parathyphi (34.2%) for bacteria and C. albicans (28.8%) for fungi whereas, lowest relative percentage inhibition against Sarcina lutea (22.0%) for bacteria and Aspergillus niger (24.4%) for fungi. In the brine shrimp lethality bioassay, The $LC_{50}$ values of Carbon tetrachloride and N-Hexane soluble fraction were found $92.18{\mu}g/mL$, and $68.95{\mu}g/mL$ respectively while the $LC_{50}$ values of standard Vincristine sulphate was $1.37{\mu}g/mL$. The methanolic extract and its organic soluble fractions of Lablab purpureus at concentration 2.0 mg/mL, significantly protected the lysis of erythrocyte membrane induced by hypotonic solution and heat as compared to the standard, acetyl salicylic acid (0.10 mg/mL). The MSF and AQSF produced 61.48 % and 53.75% inhibition of hemolysis of RBC caused by hypotonic solution respectively, whereas acetyl salicylic acid (0.10 mg/mL) showed 76.42%. Ethanol extract of L. purpures and all of its different partitions exhibited moderate thrombolytic activity of 37.25%-2.40%. Very good preliminary screening and simplified experiments were able to show the different biological activity of methanolic extract and its soluble fractions of L. purpures at a time.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.3
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• pp.63-72
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• 2011

Benzalkonium chloride is most widely used in S. Korea as a disinfectant in livestock husbandry. Inhibition of biogas potentials were investigated with three different doses of benzalkonium chloride in swine slurry. The system was operated at batch mode. The inhibition rates were 10%, 30~40% and >70% at the dose of 10ppm, 40ppm and 80ppm, respectively assuming it was zero percent in case of no dose. Enzymatic activities were analyzed to determine the enzymatic type which was inhibited by benzalkonium chloride. The acid phosphatase, alkaline phosphatase and protease were shown negatively correlated with biogas potential. Correlation of ${\alpha}$-glucosidase and biogas potentials was observed not high (p<0.01, r=-0.426) while benzalkonium chloride (r=-0.853, p<0.01) and acid phosphatase (p<0.01) with biogas potentials were significantly and negatively correlated. The effect of benzalkonium chloride on Escherichia coli were also evaluated by disc diffusion method. As increase of benzalkonium concentration, inhibition zone of anaerobic bacteria was extended. It revealed that benzalkonium chloride significantly deteriorated biogas potential through inhibition of acetogenic bacteria.

• Geosystem Engineering
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• v.21 no.5
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• pp.243-250
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• 2018

This study investigated nitrite ($NO_2{^-}$) accumulation due to FA (Free Ammonia: $NH_3$) inhibition in an anaerobic-aerobic-anoxic (AOA) process reactor to mainly treat wastewater containing 302-610 mg/L of $NH_3/NH_4{^+}-N$. Based on an experimental operation focusing on the nitrification, it was observed that $NO_2{^-}$ was accumulated in the aerobic nitrification zone as pH increased, due to inhibition of $NO_2{^-}$ conversion to $NO_3{^-}$ by FA. This result implied FA inhibition to NOB ($NO_2{^-}$-Oxidizing Bacteria) for converting $NO_2{^-}$ to $NO_3{^-}$. The objective of this study is to develop a feasible monitoring procedure for early detection of the FA inhibition toward $NO_2{^-}$ accumulation and poor nitrification. Thus, in order to rapidly assess FA concentrations, an $NH_3$ probe was utilized to measure $NH_3$ concentrations together with applying a simple model prediction using the measured $NH_4{^+}$ concentrations, the Henry's law constant of $NH_3$ and measured pH. The predictive model $NH_3$ levels were verified by a good correlation (89%) with the corresponding measured data, but the model prediction underestimated FA concentrations at less than 7.4 and a little overestimated at pH above 7.5. Interestingly, accumulated $NO_2{^-}$ levels were roughly correlated with FA levels that were observed at delayed time points. This reflects the detected FA levels can be good indicators of $NO_2{^-}$ levels with some delayed time. $NO_2{^-}$ accumulation started at measured FA concentrations of higher than approximately 3 mg/L and ceased below that FA level.

• Restorative Dentistry and Endodontics
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• v.41 no.4
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• pp.278-282
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• 2016

Objectives: Glass ionomer cements (GICs), which are biocompatible and adhesive to the tooth surface, are widely used nowadays for tooth restoration. They inhibit the demineralization and promote the remineralization of the tooth structure adjacent to the restoration, as well as interfere with bacterial growth. Hence, the present study was conducted to assess and compare the antimicrobial activity of three commercially available GICs against two cariogenic bacteria. Materials and Methods: An agar plate diffusion test was used for evaluating the antimicrobial effect of three different GICs (Fuji IX, Ketac Molar, and d-tech) on Streptococcus mutans (S. mutans) and Lactobacillus acidophilus (L. acidophilus). Thirty plates were prepared and divided into two groups. The first group was inoculated with S. mutans, and the second group was inoculated with L. acidophilus. These plates were then incubated at $37^{\circ}C$ for 24 hours. Zones of bacterial growth inhibition that formed around each well were recorded in millimeters (mm). Results: The zones of inhibition for Fuji IX, Ketac Molar, and d-tech on S. mutans were found to be $10.84{\pm}0.22mm$, $10.23{\pm}0.15mm$, and $15.65{\pm}0.31mm$, respectively, whereas those for L. acidophilus were found to be $10.43{\pm}0.12mm$, $10.16{\pm}0.11mm$, and $15.57{\pm}0.13mm$, respectively. Conclusions: D-tech cement performed better in terms of the zone of bacterial inhibition against the two test bacteria, than the other two tested glass ionomers.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.246-253
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• 2016

The antibacterial activities of thirty mushroom species belonging to Basidiomycetes and Ascomycetes, cultivated on two liquid media, were evaluated against gram-positive (Bacillus subtilis and Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria by the disk diffusion method. All of the mushrooms, except Auriporia aurea, Fomes fomentarius, and Lyophyllum shimeji, showed different antibacterial activity levels—from 9.5 mm in diameter of the inhibition zone to full inhibition of growth of the test bacteria. The antibacterial activities of Crinipellis schevczenkovi, Hohenbuehelia myxotricha, Oxyporus obducens, and Spongipellis litschaueri were observed for the first time. The antibacterial potential of culture liquids of the investigated species was higher than that of their mycelia activity. Dependence of the intensity of antibacterial activity on the culture medium was shown. The antibacterial efficiency of the most active species (Lentinus edodes, Piptoporus betulinus, and Phellinus igniarius) was verified and compared with those of some commercial antibiotics and natural essential oils of Salvia and Eucalyptus. The culture liquid of Piptoporus betulinus, obtained after cultivation on glucose-peptone-yeast culture medium, is a potential substance for further creation of antibacterial products.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.874-879
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• 2008

Tyrosinase is a key enzyme for melanin biosynthesis, and hyperpigmentation disorders are associated with abnormal accumulation of melanin pigments, which can be reduced by treatment with depigmenting agents. The methanol extract of Lespedeza cyrtobotrya $M_{IQ}$ showed inhibitory activity against mushroom tyrosinase. The active compound was purified from the methanol extract of L. cyrtobotrya, followed by several chromatographic methods, and identified as dalbergioidin (DBG) by spectroscopic methods. The results showed that DBG exhibited tyrosinase inhibitory activity with an $IC_{50}$ of $20\;{\mu}M$. The kinetic analysis of tyrosinase inhibition revealed that DBG acted as a noncompetitive inhibitor. In addition, DBG showed a melanin biosynthesis inhibition zone in the culture plate of Streptomyces bikiniensis that has commonly been used as an indicator organism. Furthermore, $27\;{\mu}M$ DBG decreased more than 50% of melanin contents on the pigmentation using the immortalized mouse melanocyte, melan-a cell.

• The Korea Journal of Herbology
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• v.25 no.2
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• pp.65-70
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• 2010

Objectives : Biological activities of marine resources have been rarely evaluated compared with other herbal medicines. In the present study, we aimed to evaluate antimicrobial activities of aqueous and ethanolic extracts of five marine resources(Porphyra tenera, Laminariae Thallus, Sargassum, Ostreae Concha, Maliotidis Concha) against Propionibacterium acnes. Methods : Aqueous axtracts of five marine resources were prepared by decocting in tenfold tap water for 3 h. Etanolic extracts were obtained by extracting five marine resources with tenfold ethanol for 72 h at room temperature. The zone of growth inhibition and minimum inhibitory concentration (MIC) were determined against P. acnes after incubation for 48 h under anaerobic condition. Results : Ethanolic extracts of Porphyra tenera exhibited potent antimicrobial effects(MIC $62.5\;{\mu}g/m{\ell}$ against KCTC3320, MIC $31.25\;{\mu}g/m{\ell}$ against KCTC5527). However, all aqueous extracts tested had no effects on the growth inhibition of P. acnes. In addition, four ethanolic extracts except Porphyra tenera showed little inhibitory effect. Conclusions : These results indicate that ethanolic extracts of Porphyra tenera has antimicrobial activities against P. acnes and also warrant further development of Porphyra tenera extracts as a natural anti-acne agent.