• Microbiology and Biotechnology Letters
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• v.22 no.1
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• pp.73-79
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• 1994

The optimum cultural temperature and time for the pullulanase production by Bacillus cereus subsp. mycoides were 35$\circ $C and 48 hrs, respectively. The addition of egg albumin and casein to the basal medium increased the enzyme production. The enzyme was purified by ammonium sulfate fractionation and DEAE-cellulose column chromatography. specific activity of the purified enzyme was 82.37 U/mg protein and yield of theenzyume activity was 62.1%. The purified enzuyme showed a single band on ployacrylamide disc gel electrophoresis and its molecular weight was estimated to be 66.,000 by SDS-polyacrylamide disc gel electrophoresis. The isoelcular point for the purified enzyme was pH 5.0. The optimum temperature and pH were 50$\circ $C and pH 6.5, respectively. The purified enzyme was stable below 40$\circ $C and in the pH range of 6.5~10.0 The pullulanase activity was greatly inhited by Ag$^{+}$, Hg$^{2+}$ and EDTA, and its heat stability was increased by the addition of Ca$^{2+}$. The tydrolysis product with the enzyme on pullulan was maltotriose.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.5
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• pp.692-700
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• 2012

The antibacterial activity of the ethanol extract of Cornus officinalis against some bacteria related to foodborne illness and food spoilage was investigated. In the case of the disc diffusion assay, clear zones due to the inhibition of proliferation by Cornus officinalis extract were 8.5~18.3 mm at $4,000{\mu}g/disc$. The inhibitory effect of Cornus officinalis was as follows: Escherichia. coli ${\geq}$ Listeria monocytogenes ${\geq}$ E. coli O157:H7 > Bacillus cereus > Staphylococcus aureus > Pseudomonas aeruginosa > Salmonella typhimurium. In addition, the MIC of Cornus officinalis extract toward B. cereus was the lowest at 1,000 ppm. The extract inhibited the growth of E. coli, L. monocytogenes, E. coli O157:H7, and Bacillus cereus throughout the growth stage. However, the growth of P. aeruginosa, S. aureus, and S. typhimurium was only inhibited by the extract during the lag phase. The constituents of all cells tested were released, especially E. coli and E. coli O157:H7. Observation of the cells using SEM demonstrated a morphological change and disruption of cells in response to treatment with Cornus officinalis extract. Based on these findings, the ethanol extracts of Cornus officinalis showed strong antimicrobial activity against all tested bacteria, indicating that Cornus officinalis can be a useful natural antimicrobial reagent.

• Food Science and Preservation
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• v.10 no.4
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• pp.547-553
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• 2003

To develop the health and functional food material from oats, this study was conducted to determine the biologiral activities(antibacterial, antioxidative and mtltmor effects) of oat bran's soluble ${\beta}$-glucans obtained from oat bran concentrate(OBC) by central composite experimental design. The antibacterial effect of oat's ${\beta}$-glucans in the concentration of 250, 500$\mu\textrm{g}$/disc was not detected by paper disc method, and no antioxidative effect of them in the concentration of 5％ by electron donating ability. The growth inhibition on tumor cell lines of oat's soluble ${\beta}$ -glucans was significantly higher in the experimental fraction of No. 7(temperature 45$^{\circ}C$, ethanol 15%, pH 6) than the other fractions(p<0.05). The maximal values of growth inhibitions on AGS, Hep3B and A549 cell lines in the cancentration of 1mg/ml are 59%, 58% and 54% respectively. In addition, the inhibition effect on three tumor cell lines of No. 1(temperature 5$^{\circ}C$, ethanol 5%, pH 6) was relatively high. From the results of response surface methodology, as the values of independent variables changed, they influenced the growth inhibition effect on this cell lines. With this on work further research is required to clarify antitumor effects.

• Korean Journal of Food Science and Technology
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• v.9 no.3
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• pp.211-219
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• 1977

Dehulled and defatted Korean cottonseed flour was extracted with alkaline solution for 30 minutes and had precipitated the crude portein by adjusting pH $1{\sim}12$. The general composition and the amino acid composition of cottonseed protein were analyzed. Crude protein was purified with sephadex G-100 and G-200, and its component had been identified by disc electrophoresis. Toxic gossypol was removed by n-hexane, acetone and other solvents. The results were as follows. (1) pH 5, pH 7 and pH 4 were the best condition of precipitation of curde protein at single, two step and water extraction, respectively. (2) The cottonseed flour which was dehulled and defatted, contained 61.3% of crude protein. (3) The protein which was isolated from cottonseed flour, contained 20% of glutamic acid, and comparatively high levels of essential amino acids. (4) Dehulled cottonseed flour contained 0.97% of total gossypol and could be romoved 70% of total gossypol by extraction with n-hexane. (5) 10-13 bands of water soluble protein were found in disc electrophoresis, and 10-12 bands in protein were isolated by single and two step procedures. (6) The cottonseed protein could be purified by sephadex G-100 and G-200. (7) 10-20% of gossypol-free cottonseed fluor could be used for animal and human comsumption.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.1
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• pp.22-28
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• 2003

Antimicrobial effect of Dansham (Saliuia miltiorrhiza Bunge) was investigated. Methanol extract of dried Dansham was fractionated to hexane, chloroform, ethylacetate, butanol and aqueous fraction. Chloroform fraction showed the highest inhibitory effect on the microorganisms such as B. subtilis, S. aureus, E. coli, L. monocytogenes and V. parahaemolyticus at 250 $\mu\textrm{g}$/disc. Chloroform fraction was further fractionated by silica gel column and thin layer chromatography (TLC). The antimicrobial compound was isolated from their fractions and its chemical structure was identified as a cryptotanshinone by GC-MS and $^1$H-NMR, $^{13}$ C-NMR.

• Journal of Auto-vehicle Safety Association
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• v.12 no.2
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• pp.7-13
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• 2020

Recently, there is a big issue of downsizing on brake system according to fuel efficiency and regenerative braking cooperation control. Especially, small cars have improved in a variety ways such as electric vehicle and smart car compared to previous small cars. So, small brake system is strongly required in the car industry. A new small brake system for light compact vehicles was proposed in this paper. For this system, the solid type disc and caliper were newly developed. And the important design factors were considered to reduce brake size. First, we calculated the temperature rise of disc through heat capacity formula and CAE analysis. Second, we analyzed the housing and carrier stiffness of caliper to select the reasonable condition. Finally, the superiorities of the developed brake system were verified by heat capacity, consumption liquid level, braking feeling, judder, wear test and regenerative braking cooperation control analysis. A developed brake system is expected to be useful for brake system of light compact platform.

• Preventive Nutrition and Food Science
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• v.10 no.2
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• pp.130-133
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• 2005

The growth inhibitiory effect of chaff vinegar against various food-borne pathogenic bacteria was evaluated. Bacterial growth was evaluated in chaff vinegar at concentrations of 15, 30, 50, 65, 80, and $100\%$ using the paper disc diffusion method and 0.5, 1.0, 1.5, 1.8, 2.0, 2.2 and $2.5\%$ in broth. In the paper disc diffusion assay, chaff vinegar showed a clear zone on both the Gram-positive bacteria; Listeria monocytogenes, Staphylococcus aureus and Gram-negative bacteria; Escherichia coli O157:H7, Salmonella Typhimurium, and Vibrio parahaemolyticus. Chaff vinegar exhibited the greatest growth inhibition for V. parahaemolyticus. The bactericidal effect of chaff vinegar on the E. coli O157:H7 was tested at concentrations ranging from 0.5 to $2.5\%$ (v/v) in the LB broth media. Chaff vinegar retarded the lag phase time of the growth curve in proportion in a concentration-dependent manner. Chaff vinegar at $2.5\%$ completely inhibited the growth of E. coli O157:H7.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.1028-1032
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• 1997

The strain No. 33, which produces cellulose-degrading enzyme, was isolated from soil. Yellow halo was identified when the culture supernatant of the strain was loaded onto agar plate containing 2.0% CMC using paper disc method. From scanning electron microscopic observation, the morphology of the stain was rod-shaped. For identification, several biochemical characteristics were tested, and this strain was identified to Bacillus sp. So, we named this strain as Bacillus sp. No. 33. The maximal growth was observed when the stain was cultured in the medium containing 1.0% glucose, 3.0% yeast extract, 0.5% $KH_2PO_4$, 0.02% $MgSO_4{\cdot}7H_2O$, pH 7.0 at $30^{\circ}C$ for 39 hours with shaking. The maximal enzyme production was accomplished using the medium containing 4.0% CMC, 2.0% yeast extract, 0.5% $KH_2PO_4$, 0.04% $MgSO_4{\cdot}7H_2O$, pH 7.0 at $30^{\circ}C$ for 42 hours with shaking.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.197-198
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• 2006

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.483-484
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• 2007