• 한국식품조리과학회지
• /
• 제27권4호
• /
• pp.17-26
• /
• 2011

본 연구는 지유 에탄올 추출물의 항균 및 항돌연변이 활성을 측정하여 새로운 기능성 소재로서의 기초자료를 얻고자 실시하였다. E. coli, E. coli O157:H7, P. aeruginosa, S. Typhimurium, L. monocytogenes, B. cereus, S. aureus의 7가지 주요 식품위해성 세균에 대한 항균활성을 검증하기 위해 paper disc diffusion assay 및 최소저해농도를 측정하였으며 24시간 동안 균의 생육억제도를 측정하였다. Paper disc assay 결과 E. coli와 E. coli O157:H7을 제외한 5가지 균에 대한 지유 에탄올 추출물의 뚜렷한 clear zone이 확인되었다. Micro-well dilution법으로 확인한 최소저해농도의 범위는 E. coli와 E. coli O157:H7을 제외한 5가지 균에 대해서 0.625~2.5 mg/mL로 나타났으며 생육억제도 실험결과도 최소 저해농도 결과와 일치하였다. Salmonella Typhimurium TA100을 이용한 Ames test 결과, 5 mg/plate의 농도에서 직접 돌연변이원인 sodium azide와 4-NQO에 대한 지유 에탄올 추출물의 항돌연변이 활성이 각각 72.42와 89.85%로 나타나 지유 에탄올 추출물의 우수한 항돌연변이 활성을 확인하였다. 본 연구를 통해 지유 에탄올 추출물이 주요 식품위해성 세균들에 대한 우수한 항균성과 직접돌연변이원에 대한 높은 항돌연변이 활성을 나타내어 천연물 유래 생리활성 소재로 이용될 수 있는 가능성을 보여주었다.

• 한국식품영양과학회지
• /
• 제45권7호
• /
• pp.1026-1034
• /
• 2016

본 실험은 식용 가능한 약용식물을 대상으로 하여 항균 활성을 검색하였다. 미생물에 대하여 약용 식물을 50 mg/mL, 100 mg/mL, 200 mg/mL의 농도로 하여 paper disc agar diffusion assay로 항균 활성을 검색한 결과 소목 추출물에서 가장 높은 항균 활성을 나타내었다. 이에 따라 소목의 에탄올 추출물과 열수 추출물을 각각 200 mg/mL, 100 mg/mL, 50 mg/mL의 농도로 하여 paper disc agar diffusion assay로 항균 활성을 검색한 결과 소목 추출물은 그람 양성균에서 높은 항균 활성을 나타내었고, 소목의 에탄올 추출물이 소목의 열수 추출물보다 높은 항균 활성을 나타내었다. 소목 에탄올 추출물과 열수 추출물의 각 분획물을 50 mg/mL의 농도로 하여 paper disc agar diffusion assay로 항균 활성을 검색한 결과 그람 양성균은 클로로포름, 에틸아세테이트, 부탄올 층에서 항균 활성을 나타내었고, 그람 음성균은 항균 활성을 나타내지 않았다. 소목의 항균 물질로 추정되는 brazilin은 주로 에틸아세테이트 분획층에 존재하므로 소목 에탄올 추출물에서 클로로포름, 에틸아세테이트, 부탄올의 항균 활성이 유사한 점으로 미루어 brazilin 외에도 다양한 항균 물질이 존재하여 이들이 복합적으로 작용하여 항균 활성을 나타내는 것으로 생각한다. 현재까지 가장 강력한 항생제로 알려진 vancomycin과의 항균 활성을 비교한 결과 50 mg/mL 농도에서 소목 75% 에탄올 추출물의 항균 활성은 vancomycin 2.5 mg/mL를 사용하였을 때와 유사한 항균 활성을 나타내었다. 소목의 추출물을 가지고 미생물에 대한 최소저해농도를 측정한 결과 C. difficile KCTC 5009, L. monocytogens ATCC 19115의 최소저해농도는 0.06 mg/mL였고, S. aureus KCTC 1916에 대한 최소저해농도는 0.03 mg/mL였다. Vancomycin의 유효혈청농도는 0.005~0.04 mg/mL로 견줄만한 항균 활성을 나타내었다. 소목추출물을 가지고 열 및 pH 안정성을 측정한 결과는 항균력은 C. difficile KCTC 5009, L. monocytogens ATCC 19115, S. aureus KCTC 1916에서 모두 대조구와 비슷하게 억제환이 생성되어 소목 추출물의 항균성 물질은 열 및 pH에 대체로 안정한 결과를 보여주었다. 상기 결과들을 종합해 볼 때 소목 에탄올 추출물이 그람 양성균에 대해 항균활성이 뛰어난 것으로 보아 소목을 그람 양성의 병원성 미생물을 억제하기 위한 항균제제 및 기능성 식품의 소재로써 활용할 수 있다고 판단된다.

• 한국치위생학회지
• /
• 제18권1호
• /
• pp.9-18
• /
• 2018

Objectives: Pleurotus eryngii is used both for edible and medicinal purposes, and has a physiological activity. The purpose of this study is to investigate the antibacterial effect of Pleurotus eryngii against six oral pathogens (Staphylococcus aureus, Streptococcus criceti, Streptococcus mutans, Streptococcus ratti, Streptococcus sobrinus, and Actinomyces viscosus). Methods: The antibacterial activities of various extracts of Pleurotus eryngii were examined by disc diffusion assay and minimum inhibitory concentration (MIC). The disc diffusion assay was performed by putting a paper disc soaked in extracts on plates inoculated bacterial cultures. The MIC of these extracts was determined by using a broth microdilution assay at a concentration ranging between 0.03 mg/ml to 15.00 mg/ml. The growth inhibition effect of extracts was measured at 600 nm for 24 hrs. Results: The antibacterial activity was confirmed against all six tested bacteria at Pleurotus eryngii ethyl acetate extract by the disc diffusion method. Acetone extract showed the antibacterial activity only against 4 strains containing Streptococcus criceti, Streptococcus mutans, Streptococcus ratti, and Actinomyces viscosus. In ethanol extract, no activity was observed against other strains except Staphylococcus aureus. MIC values of ethyl acetate extract were the same, 7.50 mg/ml in all tested bacteria. Conclusions: Pleurotus eryngii exhibited the antibacterial activity against oral pathogens (Staphylococcus aureus, Streptococcus criceti, Streptococcus mutans, Streptococcus ratti, Streptococcus sobrinus, and Actinomyces viscosus). Thus, Pleurotus eryngii may be considered as a natural antibacterial agent for treatment of dental diseases.

• 한국지역사회생활과학회지
• /
• 제24권1호
• /
• pp.27-36
• /
• 2013

This study was performed to investigate the antimicrobial effect against food-borne pathogens of Sanguisorbae officinalis L. ethanol extract. The antimicrobial activity of the ethanol extract was determined using a paper disc-diffusion method and the diameter of the clear zone was measured. The diameters of the clear zone in the presence of 10 mg of the ethanol extract were the maximum against Staphylococcus aureus among the tested 4 gram-positive bacteria and Pseudomonas aeruginosa among the tested 7 gram-negative bacteria. Analysis of the minimum inhibition concentrations (MIC) showed that the ethanol extract exhibited a similar efficacy as sorbic acid, well-known chemical preservatives. The growth inhibitory effects of the ethanol extract in the concentrations of 250, 500, 1,000 and 2,000 mg/L on food-borne pathogens were determined against Staphylococcus aureus, Bacillus subtilis, Salmonella Typhimurium and Pseudomonas aeruginosa. The growth of the microorganisms was significantly (p<0.05) inhibited by the ethanol extract in the concentrations higher than 250 mg/L. Thus, the results of the present study demonstrate that the ethanol extract exhibits antimicrobial effects against food-borne pathogens, suggesting that Sanguisorbae officinalis L. could be used as natural antibacterial agent in food.

• 동아시아식생활학회지
• /
• 제26권3호
• /
• pp.215-222
• /
• 2016

This study was carried out to investigate the antimicrobial and anti-inflammatory activities of ethanol extract from Glycyrrhizae radix (GR) and ethanol extract from Glycyrrhizae radix cultured with Paecilomyces japonica mycelium (GRPM). Antimicrobial activity was measured by paper disc diffusion assay and minimum inhibitory concentration (MIC). Anti-inflammatory activity was evaluated by measurement of NO production in LPS-stimulated RAW264.7 cells. For the results of the paper disc diffusion assay, GRPM showed high antimicrobial activities against Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus. In addition, the MIC of GRPM (100 ppm) was lower than that of GR (200 ppm) against L. monocytogenes. When the morphology of L. monocytogenes treated with GRPM was observed using a FE-SEM, the surface of cells treated with GRPM were damaged, and some parts of the cell wall were destroyed. The inhibitory effect on NO production in LPS-stimulated RAW264.7 cells was significantly increased by GRPM treatment. In conclusion, GRPM is superior to GR in terms of antimicrobial and anti-inflammatory activities.

• Preventive Nutrition and Food Science
• /
• 제10권2호
• /
• pp.130-133
• /
• 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.

• 한국식생활문화학회지
• /
• 제16권3호
• /
• pp.243-249
• /
• 2001

Antibacterial activities in each part of watercress(Oenanthe javanica D.C.) grown under different culture conditions were measured to determine the possibility to use watercress as a resource to develop the antibacterial substance. The leaves of watercress were extracted with methanol and the methanol extract was further fractionated with various organic solvents. Antibacterial activities against Shigella dysenteriae ATCC 9361 in all fractions were determined according to the agar diffusion method using paper disc. Methanol extract of watercress leaves was more effectively inhibited the growth of the tested bacteria than the extracts of roots or stems at the concentration of 0.5 g eq./disc, and the extract of watercress from Hwasoon was the most effective one as compared to others. Phenolic and neutral fractions fractionated from methanol extract of watercress had a considerable inhibiting activity on the growth of the bacteria, but acidic and basic fractions did not show any inhibitory effect. Minimum inhibitory concentrations of phenolic and neutral fractions against Shigella dysenteriae ATCC 9361 were $400\;{\mu}g/disc$ and $550\;{\mu}g/disc$, respectively.

• 생명과학회지
• /
• 제29권7호
• /
• pp.785-791
• /
• 2019

본 연구에서는 편백나무(Chamaecyparis obtusa) 추출액의 항산화 활성 및 항균활성을 검토하였다. 편백나무 추출액의 항산화 활성을 평가하기 위하여 DPPH radical 소거능, ABTS radical 소거능 및 SOD 유사 활성을 분석하였다. 그 결과, 편백나무 추출액의 DPPH radical 및 ABTS radical 소거 활성은 농도 의존적으로 증가하였으며, $50{\mu}l/ml$ 농도에서 78% 및 62%의 최대 활성을 나타내었다. 또한, 편백나무 추출액은 높은 SOD 유사 활성을 보였으며, $50{\mu}l/ml$ 농도에서 92.85 %의 최대 활성을 나타내었다. 한편, 편백나무 추출액의 항균 활성을 측정하기 위해 Paper disc agar diffusion 법을 이용하여 식중독 및 질병을 일으키는 6종의 균주에 대하여 검토하였다. 편백나무 추출액은 B. cereus, E. coli, L. monocytogenes, S. aureus, S. typhi, V. parahaemolyticus에 대한 항균 활성이 나타났고, 이중 B. cereus에 대하여 가장 강한 항 박테리아 활성을 보였다. 이상과 같이 항균 활성이 나타난 6종의 균주에서 편백나무 추출액의 MIC 및 MBC는 $30{\sim}40{\mu}l/ml$로 확인되었다. 이러한 결과는 편백나무 추출액을 이용하여 식중독과 같은 병원균의 성장을 억제하는 항균 소재로 개발한다면 산업적 가치가 높을 것으로 생각된다.

• 한국정밀공학회지
• /
• 제15권2호
• /
• pp.28-34
• /
• 1998

Powder metallurgy processes are able to form Net-Shape products and have been widely used in the production of automobile parts to improve its productivity. However, because of pores in powder products, the toughness of powder products are generally poor. Therefore, forged products are used in parts which suffer severe fatigue loads. In this paper, the choice of powder materials and production processes such as mixing, compaction, sintering, heat treatment to produce automobile spline hub are studied. Three type of materials are selected and processed and its microstructure and properties are investigated by tensile test, compression ring test, and impact test. Materials and processing methods are selected from the results. Finally, experimental spline hubs are manufactured by selected processes from selected powders and proved by torsional durability test.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2004년도 ICCAS
• /
• pp.312-316
• /
• 2004

The paper presents a technique to identify the boundary of the optic disc in infant retinal digital images using an approach based on active contours (snakes). The technique can be used to be develop a automate system in order to help the ophthalmologist's diagnosis the retinopathy of prematurity (ROP) disease which may occurred on preterm infant,. The optic disc detection is one of the fundamental step which could help to create an automate diagnose system for the doctors we use a new kind of active contour (snake) method has been developed by Chenyang et. al. [1], based on a new type of external force field, called gradient vector flow, or GVF. GVF is computed as a diffusion of the gradient vectors of a gray-level or binary edge map derived from the image. The testing results on a set of infant retinal ROP images verify the effectiveness of the proposed methods. We show that GVF has a large capture range and it's able to move snakes into boundary concavities of optic disc and finally the optic disk boundary was determined.