Evaluation of the Growth Activity of Escherichia coli and Staphylococcus aureus Colonies on Solid Medium Using Microbial Calorimetry
スポンサーリンク
概要
- 論文の詳細を見る
The colonial growth of <I>Escherichia coli</I> and <I>Staphylococcus aureus</I> on agar solidified medium (a food model system) was estimated by using a microbial calorimeter. Changes in the metabolic heat of the colonial growth over time (the growth thermogram) were obtained with good reproducibility. The actual heat evolution curves [<I>f</I> (<I>t</I>) curves] obtained from the thermograms of growing colonies gave good agreement with the changes in viable cell numbers in colonies under the same conditions. The <I>f</I> (<I>t</I>) curve was also compared with the process of colony formation. During the early period of the <I>f</I> (<I>t</I>) curve (the period of 0 - 10h after inoculation), colonies could not be observed, but at 15h after inoculation, some small colonies were visible. During the period between 15h and 25h, the numbers and size of colonies increased. During the later period of the <I>f</I> (<I>t</I>) curve (the period of 25-34h), although the size of colonies still increased, the colonial profiles on LBA medium were almost similar in spite of the continued evolution of growth heat, indicating that the direction of colony growth shifted from being predominantly radial to predominantly.vertical with regard to the agar surface. From the logarithmic <I>f</I> (<I>t</I>) curve, the exponential growth phase was estimated to be the period between 8.5 h and 13.5 h after inoculation. The growth rate constants (μ') for colonial growth obtained from the <I>f</I> (<I>t</I>) curves were 0.643±0.037 h<SUP>-1</SUP> for <I>E. coli</I> and 0.597±0.05811<SUP>-1</SUP> for <I>S. aureus</I>. The suppressive activities of salts and kumazasa (<I>Sasa albo-marginata Makino et Shibata</I>) extracts on colonial growth were evaluated in terms of μ<SUB>i</SUB>' μ<SUB>m</SUB>' derived from the <I>f</I> (<I>t</I>) curves. The MIC (minimum ihhibitory concentration) values for NaCI were estimated to be 9.7±1.5%, equivalent to a water activity (Aw) of around 0.906, against <I>E. coli</I> colonial growth and 12.8±1.4%, equivalent to an Aw of around 0.882, against <I>S. aureus</I>. The MIC value for kumazasa extracts was estimated to be 4.6±0.6% (1.79 mg of non-volatile components per 1 ml) against <I>S. aureus</I> colonial growth. These values were in good agreement with those obtained by the agar plate dilution method. The study of bacterial growth on solid medium, as opposed to traditional liquid culture, should provide a model system more representative of the food environment. Microbial calorimetry is a method suitable for non-destructive growth measurements of microbial colonies on solid medium.
- 日本防菌防黴学会の論文
- 2004-06-20
著者
-
Koga Kunimasa
School Of High Technol. For Human Welfare Tokai Univ.
-
Hara Takaaki
Hakuju Life Science Co.
-
NISHIZAWA YU
School of High Technology for Human Welfare, Tokai University
-
MATSUMOTO YOU-ICHI
School of High Technology for Human Welfare, Tokai University
-
TAKAHASHI KATSUTADA
Keihanna Academy of Science and Cultures.
-
Matsumoto You-ichi
School Of High Technology For Human Welfare Tokai University
-
Nishizawa Yu
School Of High Technology For Human Welfare Tokai University
-
TAKAHASHI KATSUTADA
Keihanna Academy of Science and Cultures
関連論文
- Effect of a seaweed mixture on serum lipid level and platelet aggregation in rats
- Inhibitory effects of L-pipecolic acid from the edible mushroom, Sarcodon aspratus, on angiotensin I-converting enzyme
- マウスのストレス性胃炎に対する酸性キシロオリゴ糖の抑制作用
- Antioxidant Activities of Acidic Xylooligosaccharide
- Preventive Effects of Acidic Xylooligosaccharide on Contact Hypersensitivity in Mice
- Antioxidant and Antiinflammatory Activities of Oregano Extract
- Anti-Diabetic Activity of a Leaf Extract Prepared from Salacia reticulata in Mice
- Evaluation of Growth Activity of Microbes in Tea Field Soil Using Microbial Calorimetry
- 有機肥料施用による茶畑土壌微生物の増殖活性の向上
- Calorimetric Evaluations of Bacillus subtilis Vegetative and Spore Cells Colonial Growth and Suppressive Effects of Sucrose Monopalmitate
- Evaluation of the Growth Activity of Escherichia coli and Staphylococcus aureus Colonies on Solid Medium Using Microbial Calorimetry
- Fermentation of non-sterilized fish biomass with a mixed culture of film-forming yeasts and lactobacilli and its effect on innate and adaptive immunity in mice(BREWING AND FOOD TECHNOLOGY)