• 생약학회지
• /
• 제34권2호통권133호
• /
• pp.142-144
• /
• 2003

Acetone extracts of 301 strains of marine-derived fungus were tested for antimicrobial activity against three strains of bacteria. The bacteria consisted of three pathogens, Staphylococcus aureus, methicillin-resistant S. Aureus, and multidrug-resistant S. aureus. The acetone extracts of 10 strains (MFA117, MFA130, MFA134, MFA206, MFA217, MFA268, MFA277, MFA291, MFA292, MFA301) showed strong activity, inhibiting 100% of the bacterial growth. These antimicrobial active strains were cultlued in SWS medium on a 1 L scale and the resulting broth and mycelium were extracted to afford mycelium extract (000M) and broth extract (000B), respectively. Antimicrobial activity for all extracts has been tested as the results, the mycelium extract of one strain (217M) and the broth extracts of 9 strains (117B,130B, 134B, 206B, 268B, 277B, 291B, 292B, 301B) exhibited relatively high levels of activity at minimal inhibitory concentration (MIC) values of $500-125\;{\mu}g/mL$ range. Among them, the extracts, 277B, 291B, 292B and 301B showed the most significant antimicrobial activity with $IC_{50}$ values of $125\;{\mu}g/mL$.

• 한국미생물·생명공학회지
• /
• 제16권2호
• /
• pp.119-125
• /
• 1988

Cellulomonas sp. CS1-1 생성의 $\beta$-glucosidase는 cell-bound 효소이었으며, Avicelase와 Carboxymethyl-cellulase (CMCase)는 extracellular 효소로 존재함을 확인하였다. Cellobiose나 CMC 최소배지에서의 균의 생장은 cellobiose보다 glucose 첨가시에 현저히 증가하였다. Cellobiose나 CMC 최소배지에서의 $\beta$-glucosidase 생합성은 glucose 첨가로 현저히 억제되었으나, CMC 최소배지에 cellobiose를 첨가하였을 경우, glucose에 의한 억제 효과와는 반대로, 효소의 생성은 오히려 촉진되었다. 그 외의 탄소원에 관한 영향을 조사한 결과 CMC, 전분, maltose 등의 첨가도 glycerol, arabinose, xylose, trehalose의 첨가시 보다 효소의 생성이 증가되었다. 이상의 결과로 $\beta$-glucosidase 생합성은 glucose에 의하여 catabolite repression을 받았으며, cellobiose, CMC, starch등은 다른 당류보다 효소생성을 현저히 유도하였으므로, 이 효소는 inducible enzyme임을 알 수 있었다. 효소생성에 미치는 질소원을 조사한 결과는 yeast extract가 peptone이나 ammonium sulfate보다 효소생성을 증가시켰다. 효소의 특성을 조사한 결과, 50mM MgCl$_2$가 포함된 10mM potassium phosphate buffer (pH 7.0)에서 효소의 역가가 증가하였고, 최적 pH는 6.0이었고 최적온도는 42$^{\circ}C$ 이었다. p-nitrophenyl-$\beta$-D-glucoside의 농도에 대한 glucose의 Km값은 0.265mM 이었고 $\beta$-D(+)-glucose에 대한 Ki값은 9.0 mM 이었다.

• Archives of Pharmacal Research
• /
• 제17권6호
• /
• pp.438-442
• /
• 1994

Antimicrobial activity of GL (the aqueous extract from the carpophores of Ganoderma lucidum ($F_RK_{KARST}$) was tested in vitro aginst Gram positive and Gram negative bacteria by serial broth dilution method, and the antimicrobial activity was expressed by minimal inhibitory concentration (MIC). Among fifteeen species of bacteria tested, the natimicrobial activity of GL was of antimicrobial combinations of GL with four kinds of antibiotics (ampicilin, cefazolin, oxytet-racycline and chloramphenicol), the fractional inhibitory concentraction index (FICI) was determined by checkerboard assy for each stain. The antimicrobial combinations of GL with four antibiotics resulted in additive effect in most instances, synergism in two instances, and antagonism in two instances. Synergism was obversed when GL was combined with cefazolin against Bacillus subtilis and Klebsiella oxytoca.

• International Journal of Oral Biology
• /
• 제39권2호
• /
• pp.115-120
• /
• 2014

Minimal inhibitory concentration (MIC) is the lowest concentration of antibiotics that inhibits the visible growth of a microorganism. It has been reported that sub-MIC of antibiotics may result in morphological alterations along with biochemical and physiological changes in bacteria. The purpose of this study was to examine morphological changes of periodontal pathogens after treatment with sub-MIC antibiotics. Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis were used in this study. The MIC for amoxicillin, doxycycline, metronidazole, penicillin, and tetracycline were determined by broth dilution method. The bacterial morphology was observed with bright field microscope after incubating with sub-MIC antibiotics. The length of A. actinomycetemcomitans and F. nucleatum were increased after incubation with metronidazole; penicillin and amoxicillin. P. gingivalis were increased after incubating with metronidazole and penicillin. However, F. nucleatum showed decreased length after incubation with doxycycline and tetracycline. In this study, we observed that sub-MIC antibiotics can affect the morphology of periodontal pathogens.

• 한국축산식품학회지
• /
• 제34권4호
• /
• pp.448-456
• /
• 2014

Studies on the flavour characteristics of meat-based broth, quantification of flavour-related and functional compounds, and factors affecting the availability of such compounds are minimal. The present study was designed to determine the effects of sex on flavor-related and functional compounds in freeze-dried broth (FDB) made from Korean native chickens (KNC). Male and female KNC from a commercial strain (Woorimatdag$^{TM}$) were reared under similar commercial conditions. FDB was separately prepared using male and female birds aged 100 d (six birds of each sex) and analyzed for nucleotide, free amino acid, betaine, carnitine, carnosine, anserine, and creatine contents, and fatty acid composition. The levels of betaine, carnitine and creatine in FDB were not significantly different between the two sexes (p>0.05) in KNC. Carnosine and anserine were not detected in FDB samples. However, FDB from female chickens had significantly higher inosine-5-monophosphate and arachidonic acid contents than did FDB from male chickens. FDB prepared with male KNC contained higher levels of inosine, linoleic acid, glycine, alanine, lysine, and serine (p<0.05). However, glutamic acid, oleic acid, and DHA were present in comparable amounts (p>0.05) in FDB made from male and female KNC. Our findings suggest that the sex of KNC has significant effect on the contents of flavor-related compounds, but not functional compounds.

• Preventive Nutrition and Food Science
• /
• 제5권3호
• /
• pp.131-135
• /
• 2000

The inhibitory effect of various organic acids on the growth and survival of Escherichia coli O157:H7 in tryptic soy broth with 0.6% yeast extract at 37$^{\circ}C$ or 4$^{\circ}C$ was determined. Minimal inhibitory pHs of acetic acid, citric acid, fumaric acid, hydrochloric acid and lactic acid were 5.0, 4.0, 4.5, 4.0 and 4.5, respectively. Acetic acid (0.012 m) showed the strongest antimicrobial activity, based on the pH values or equivalent molar concentrations, followed by lactic acid (0.0006 M), fumaric acid (0.004M) and citirc acid (0.004 M), respectively, E. coli O157:H7 with an initial inoculum of {TEX}$10^{7}${/TEX} CFU/ml and {TEX}$10^{5}{/TEX} CFU/ml in tryptic soy broth supplemented with 0.6% yeast extract, acidified to target pH with citric, fumaric and lactic acids at 37$^{\circ}C$, was completely inactivated after 7 d and 5 d incubation, respectively, except for the acetic acid (9 d). The bactericidal effect decreased at the same pH when the incubation temperature a was reduced from 37$^{\circ}C$ to 4$^{\circ}C$. The pH values of 0.2% acetic (pH 5.1), 0.6% citric (pH 4.2) and 0.4% lactic acid (pH 4.3) in TSBYE were almost correspondent to the minimal inhibitory pH values on E. coli O157:H7 of acetic (pH 4.0), citric (pH 4.0) and lactic acids (pH 4.5).

• 한국식품위생안전성학회지
• /
• 제19권1호
• /
• pp.25-30
• /
• 2004

숙주나물과 콩나물은 blanching후 변질 속도가 크게 차이가 나는 바 이들이 Bacillus subtilis, Bacillus cereus, Pseudomonas fluorescens, Listeria monocytogenes등 4종의 부패성 및 식중독 미생물의 증식에 미치는 영향을 조사하였다. 숙주나물과 콩나물의 조리과정 중 blanching조건이 달라 각각의 조건에서 두 시료 모두 blanching하여 생균수를 측정한 결과 blanching 한 후 미생물 수는 저장시간에 따라 증가하나 그 차이가 없었다. 최소배지에 숙주나물과 콩나물 농축물 및 부패성 미생물을 접종한 후 생균수를 측정한 결과 숙주나물에 접종한 모든 균들의 초기 균수가 높았으나 24시간 이후 비슷한 증식양상을 나타내었다. 그러나 숙주나물과 콩나물의 여액을 배지로 사용하여 실험한 결과 미생물의 증식 양상은 균주 마다 다른 것으로 나타났다. 저장기간 동안 색도를 측정한 결과 숙주나물의 경우 24시간에는 색차가 거의 없다가 48시간 이후 현저한 차이를 보였고, 콩나물의 경우 24시간에 다른 계통의 색으로 변하다가 48시간 이후 현저하게 많은 차이를 보여 다른 양상을 나타내었다.

• KSBB Journal
• /
• 제14권6호
• /
• pp.737-741
• /
• 1999

본 연구에서 분리된 phenanthrene 분해균주의 대부분이 소수성을 나타내었고, 미생물계면활성제를 생산하면서 분해하는 균주보다 phenanthrene 분해능이 높았다. 균주 H6의 경우 phenanthrene 분해시 생산되는 미생물계면활성제는 포도당을 분해할 때도 생산되면 미생물의 성장과 더불어 증가하다가 stationary phase에서 일정하게 유지되었다. H6는 Bacillus subtilis로서 분리된 미생물계면활성제는 lipopeptide이었으며 H6에서 추출한 미생물계면활성제는 pH 2 이하에서 거의 회수되었고, 분산력이 Tween 80이나 Brij 30 등 화학계면활성제보다 높았고 열에 강한 특성을 보였다.

• Journal of Periodontal and Implant Science
• /
• 제26권1호
• /
• pp.202-215
• /
• 1996

The purpose of this study was to an in estigate the antibiotic susceptibiliity of Actinoobacillus actinomycetemcomitans isolated from the subgingival plaque to adult periodontitis. Seven bacterial strains were tested for their susceptibility to 10 antimicrobial agents under disk diffusion method and broth dilution methold, Seven patients with deep pocket(6mm) were selected for this study. They had not taken antibiotics for 6 months and no history of dental treatment for 6 months and no history of dental treatment for 6 months before this study. The results were as follows : 1. For the antibiotic disk diffusion method, seven A. actinimycetemcomitans were tested with 10 antimicrobial agents which comprised penicillin, gentamycin, clindamycin, lincomycin, ampicillin, erythromycin, tetracycline, amikacin, chloramphenicol, and vancomycin. The sensitive antibiotics were tetracycline, vancomycin, and chloramphenicol and the resistant antibiotics were clindamycin, and lincomycin. The other antimicrobial agents were less active. 2. From the study of determination on the minimal inhibitory concentration(MIC) by broth dilution method, the MIC of tetracycline to seven strains of the A. actinomycetemcomitans was $0.5-1.0{\mu}g/ml$, that of clindamycin was $32{\mu}g/ml$. These data suggest that tetracycline may be valuable drugs in the elimination of A. actinimycetemcomitans from the patients with adult periodontitis

• 한국응용곤충학회지
• /
• 제50권4호
• /
• pp.307-314
• /
• 2011

동충하초는 예로부터 아시아권에서 한방약재로 사용되어 온 곤충병원성진균이다. 이 중 노린재동충하초(Cordyceps nutans)는 자연 상태에서 비교적 많이 발견되나 이에 대한 연구가 미미한 편이다. 따라서 본 실험에서는 C. nutans 균사체의 최적 배양 조건을 확립하고 배양액 처치 시대식세포의 NO (nitric oxide) 생성 억제 효능을 조사하였다. 균사 생육 적정 온도는 $25^{\circ}C$이었으며 pH는 7.0~8.0 사이의 중성범위로 조사되었다. MCM (mushroom complete medium), V8A (V8 juice agar), YMD (yeast malt dextrose) 배지에서는 균사 생육이 우수하였으나 MMM (mushroom minimal medium) 배지의 경우 균사 생육이 이루어지지 않아 영양원이 필수적이었다. 영양원 선발에 있어 탄소원은 dextrose와 sucrose가 적합하였고 질소원은 ammonium citrate가 균사 생장에 적합하였다. RAW 264.7 세포에 대한 C. nutans 배양액의 세포 독성은 나타나지 않았으며 LPS (lipopolysaccharide)를 처리 한 세포의 NO 생성량은 농도 의존적으로 줄어들었다. 따라서 본 실험 결과는 C. nutans 배양 시 다량의 균사체를 확보할 수 있는 최적 조건을 제공할 뿐 아니라 C. nutans의 항염 관련 우수한 생리 활성이 있음을 보여준다.