• Mycobiology
• /
• v.30 no.2
• /
• pp.93-95
• /
• 2002

The antifungal activities of propolis on Cryptococcus neoformans and Candida albicans were evaluated. In microbroth culture assay, the MIC(minimum inhibitory concentration) of propolis for C. neoformans and C. albicans were 2 and 16 mg/ml, respectively. In propolis-included solid medium assay, the MIC of propolis for C. neoformans and C. albicans were 4 and 16 mg/ml, respectively. Propolis showed fungicidal activity against C. neoformans, whereas propolis possesed fungistatic activity against C. albicans. The MFC(minimum fungicidal concentration) for C. neoformans was 8 mg/ml. Cell morphology of C. neoformans was affected by treatment of propolis. In scanning electron microscope, the appearance of cell rupture was observed.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.4
• /
• pp.465-474
• /
• 2014

This study was performed to investigate the inhibitory effects of brown algae extracts on histamine production in mackerel muscle. First, antimicrobial activities of brown algae extracts against Morganella morganii were investigated using a disk diffusion method. An ethanol extract of Ecklonia cava (ECEE) exhibited strong antimicrobial activity. The minimum inhibitory concentration (MIC) of ECEE was 2 mg/ml. Furthermore, the brown algae extracts were examined for their ability to inhibit crude histidine decarboxylase (HDC) of M. morganii. The ethanol extract of Eisenia bicyclis (EBEE) and ECEE exhibited significant inhibitory activities (19.82% and 33.79%, respectively) at a concentration of 1 mg/ml. To obtain the phlorotannin dieckol, ECEE and EBEE were subjected to liquid-liquid extraction, silica gel column chromatography, and HPLC. Dieckol exhibited substantial inhibitory activity with an $IC_{50}$ value of 0.61 mg/ml, and exhibited competitive inhibition. These extracts were also tested on mackerel muscle. The viable cell counts and histamine production in mackerel muscle inoculated with M. morganii treated with ${\geq}2.5 $ MIC of ECEE (weight basis) were highly inhibited compared with the untreated sample. Furthermore, treatment of crude HD-Cinoculated mackerel muscle with 0.5% ECEE and 0.5% EBEE (weight basis), which exhibited excellent inhibitory activities against crude HDC, reduced the overall histamine production by 46.29% and 56.89%, respectively, compared with the untreated sample. Thus, these inhibitory effects of ECEE and EBEE should be helpful in enhancing the safety of mackerel by suppressing histamine production in this fish species.

• Korean Journal of Food Science and Technology
• /
• v.49 no.2
• /
• pp.146-150
• /
• 2017

Staphylococcus aureus is a pathogenic bacterium that causes food poisoning, exhibits a strong capacity to form biofilm, and is highly resistant to antimicrobial agents. The purpose of this study was to investigate the antimicrobial characteristics of corosolic acid against S. aureus. S. aureus showed high susceptibility to corosolic acid in a concentration-dependent manner. The minimum inhibitory concentration and colony-forming ability determined by the broth microdilution method showed that corosolic acid had strong antimicrobial activity against the bacteria. The diameters of the inhibition zone and numbers of colony forming units at each concentration of corosolic acid were also measured. In addition, corosolic acid displayed potent biofilm inhibition activity against S. aureus at concentrations below its minimum inhibitory concentration. These results suggest that corosolic acid can be used to effectively prevent biofilm formation by S. aureus, thereby making S. aureus more susceptible to the action of antimicrobials.

• Food Science and Preservation
• /
• v.5 no.3
• /
• pp.299-304
• /
• 1998

Screening for antibacterial activities with microorganisms related to the food putrefaction by ethanol extract from Chrysanthemum petals widely used for the traditional wine production, and antibacterial activities of each concentration and minimum inhibitory concentration(MIC) from the ethanol extract were researched. Antibacterial activity of ehanol extract for B. subtilis was higher in C. boreale than in C. Morifolium, but that of E. coli was higher in C. molifolium than in C. boreale. C. boreale was higher than C. morifolium in the antibacterial activity of ehanol extract and MIC of ehanol extract from C. boreale was 60-70${\mu}\ell$/ml. Ethanol extract from C. boreale was higher Gram(-) than Gram(+) in the antibacterial activities, but Gram(-), Gram(+) were greatly inhibited on growth in 100${\mu}\ell$ concentration.

• Journal of Oral Medicine and Pain
• /
• v.35 no.1
• /
• pp.19-29
• /
• 2010

Phytoncide, essential oil of trees, has microbicidal, insecticidal, acaricidal, and deodorizing effect. The present study was performed to examine the effect of phytoncide on Candida albicans, which is a commensal colonizer of the mucous membranes but has become an opportunistic pathogen. C. albicans was incubated with or without phytoncide extracted from Hinoki (Chamaecyparis obtusa Sieb. et Zucc.; Japanese cypress) and then changes were observed in its optical density, cell viability and morphology. As concentrations of phytoncide added to the culture medium increased, optical density and cell viability of C. albicans decreased. Minimum inhibitory concentration of phytoncide for C. albicans was observed to be 0.25%, and minimum fungicidal concentration was 0.5%. Numbers of morphologically atypical cells with electron-dense cytoplasm and granules and increased with increasing concentration of the phytoncide. At higher concentrations of phytoncide, compartments and organelles in the cytoplasm became indistinguishable. The overall results indicate that the phytoncide used for this study has a strong antimicrobial activity against C. albicans. Therefore, the phytoncide may be used as a candidate for prevention and therapeutic agent against oral candidiasis.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.46 no.2
• /
• pp.135-138
• /
• 2019

The aim of this study was to investigate the susceptibility of Mutans streptococci in both planktonic and biofilm states to erythrosine. S. mutans was cultured in brain-heart infusion (BHI) broth. Erythrosine was diluted in BHI broth and prepared at a concentration range of $0.02-10000{\mu}g/L$. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were measured using the microdilution method. After forming biofilms on 96-well plates, the minimum biofilm inhibitory concentration (MBIC) and minimum biofilm eradication concentration (MBEC) were measured. S. mutans was susceptible to erythrosine in both planktonic and biofilm states. MIC and MBC values were both $19.5{\mu}g/L$ for the planktonic state, while MBIC and MBEC values were $313{\mu}g/L$ and $2500{\mu}g/L$, respectively, for the biofilm state. Erythrosine ($19.5{\mu}g/L$) exhibited a bactericidal effect on S. mutans (killing 99.9%) in the planktonic state. For biofilms, erythrosine inhibited biofilm growth and eradicated 99.9% of biofilm bacteria at higher concentrations than MIC and MBC. These MBIC and MBEC concentrations are much lower than known noxious doses, and the MIC, MBC, and MBIC values were even lower than clinical concentrations.

• Mycobiology
• /
• v.28 no.3
• /
• pp.123-126
• /
• 2000

Sodium hypochlorite alkaline was tested against Pseudomonas tolaasii causing bacterial blotch on cultivated oyster mushroom (Pleurotus ostreatus). The minimum inhibitory concentration of sodium hypochlorite against P. tolaasii contained active chlorine (AC) at 1.4 mg/l on plate assay. The highest cultivation yield was obtained from the treatment of AC 5.7 mg/l. Treatment of sodium hypochlorite at the rate of higher than AC 11.4 mg/l resulted in reduced yields at the harvest. However, the population of total bacteria on the bed surface treated with AC 5.7 mg/l of sodium hypochlorite was maintained to some extent. Inhibitory concentration against total bacteria on the bed surface was over AC 22.8 mg/l. Mushroom mycelium was damaged and its growth strongly inhibited at the concentration of AC 200 mg/l. Mushroom caps showed yellowish symptom by chemical injury by treatments of AC 74.1 mg/l or higher. Sporocarps infected by P. tolaasii were irrevocable at any concentration of sodium hypochlorite. Routine watering with AC 5.7 mg/l from mushroom initiation to the end of picking resulted in reduced bacterial blotch incidence of 40% and 86% at two mushroom farms. The treatment resulted in higher quality mushroom production compared to that conventionally watered with tap water alone.

• Korean Journal of Pharmacognosy
• /
• v.32 no.1 s.124
• /
• pp.55-60
• /
• 2001

The comparison of $IC_{50}$ values of Salvia plebeia R. Br. extracts on L1210, $P388D_1$ cancer and Vero normal cell lines showed that the n-hexane soluble extract of S. plebeia R. Br. retains the most growth-inhibitory activity against tumor cell lines. The minimum inhibitory concentration (MIC) of the extract against microorganisms were also examined. Antimicrobial activity of amocla and ketoconazole as references was compared to those of other solvent extracts such as $H_2O$, n-hexane, chloroform, ethyl acetate and methanol. The antimicrobial activity of extract had growth inhibition activity against gramnegative bacteria, gram-positive bacteria and fungi $(MIC\;>\;200\;{\mu}g/ml)$ except for n-hexane extract. Seven bacterial strains were tested for in vitro susceptibility to the extract of S. plebeia R. Br. However the n-hexane extract of S. plebeia R. Br. inhibited the growth of several bacterial strains (MIC values between 100 and $200\;{\mu}g/ml$ for gram positive bacteria, $25\;{\mu}g/ml$ for P. putida).

• YAKHAK HOEJI
• /
• v.34 no.6
• /
• pp.434-438
• /
• 1990

The methanolic extract of the root-bark of Morus alba L.(Mulberry tree) has the potent antibacterial activity against Streptococcus mutans. Its active component was identified to be sanggenon C. The active component had stronger anti-bacterial activity than berberine, having minimum inhibitory concentration(MIC) of $25\;{\mu}g/ml$. Moreover, the inhibitory effect of this component on the cellular adherence of Streptococcus mutans to glass surfaces also was more remarkable than that of berberine in the presence of glucosyltransferase(GTase) and sucrose in vitro. These results indicate that sanggenon C may play an important role in inhibiting plaque formation and caries incidence.

• Korean journal of food and cookery science
• /
• v.27 no.1
• /
• pp.1-9
• /
• 2011

Anti oralmicrobial effects of Nulembo nucifera were determined against S.mutans, S.sobrinus S.sobrinus, F.nucleatum, and A.actinomycetemcomitans using paper disc method, minimum inhibitory concentrate (MICs). Extracts of lotus leaf showed the highest yield. MeOH extract is 21%, Chloroform fraction is 4.2%, ethylacetate fraction is 8.2%, water fraction is 19%. Different parts such as flower, leaf, seed and pod showed antimicrobial effects against S.mutans, with flower and seed extracts showing strong antimicrobial effect aganinst S.sobrinus KCCM11897. Leaf extract(1000pm concentration) showed over 50% inhibitory effect against S.mutans and S.sobrinus KCCM11897. Flower extract showed over 40% inhibitory effect against F.nucleatum and A.actinomycetemcomitans. MICs of flower extract against S.sobrinus KCCM11897,11898 and leaf extract against S.mutans, S.sobrinus KCCM11897 were $625\;{\mu}g/ml$, indicating Nulembo nucifera extract can exert antimicrobial activity even at low concentration. All extractes with heat at $120^{\circ}C$ had antimicrobial activity, which means that is a very stable substances. F.nucleatum and A.actinomycetemcomitans was stable against acid it had a trend that the more akali side was the lower acitivity.