• Food Science and Biotechnology
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• 제15권3호
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• pp.458-461
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• 2006

To determine whether the toxicity of Bacillus cereus would be seen in human cell lines and mice, we screened B. cereus B-38B, B. cereus B-50B, and B. cereus KCCM40935 for genes that coded for 5 enterotoxins using the polymerase chain reaction and cultivated them for 17 hr, by whose time they had grown to $10^7-10^8$ colony-forming units (CFU) per milliliter. Cell-free supernatant was added to make up 1% of the total reaction solution. Human cells from normal lung, lung carcinoma, embryonic kidney, and cervical adenocarcinoma cell lines were grown in culture. The cytotoxicity induced by adding the reaction solution was indicated by cell death rates of 0 to 70%, depending on the bacterial strain involved and the cell line. A lethality of 20% was observed when B. cereus cultures containing $10^7-10^8$ viable cells were administrated orally to mice. Therefore, the culture of B. cereus containing $10^7-10^8$ viable cells seems to have high cytotoxicity on human cell lines and lethality on mice.

• 치과방사선
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• 제27권1호
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• pp.107-122
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• 1997

Radiation sensitivity data was generated for two human cancer cell lines(KB, RPMI 2650) and human primary gingival fibroblast was tested three times using a viable cell number counting with a hemocytometer, MTT(3-[4,5-Dimethylthiazol2-yl]-2,5-diphenyl tetrazolium bromide) assay, and LDH(Lactate dehydrogenase) assay. Single irradiation of 2, 4, 6, 10, 15, 20Gy were applied to the tumor cell lines and the primary cultured gingival fibroblast The two fractions of 4Gy and 10Gy were seperated with a 4 hour time interval. The irradiation was done with 241.5cGy/min dose rate using /sup 137/Cs MK cell irradiator at room temperature. The obtained results were as followed : 1. There was significantly different viable cell numbers as the amount of radiation dose on the tested cells were cell number counted with a hemocytometer. In fractions, there were more viable cells remaining. 2. Phase-contrast microscopically, radiation-induced morphologic changes were pronounced on the tumor cells, however, almost no differences on the gingival fibroblast. 3. There was significantly different absorbance at 2Gy on RPMI 2600, 4Gy on KB and GF in MTT assay. In fractions, the absorbance was significantly higher on KB. 4. The level of extracellular LDH activity in the experimental group was significantly higher in the 2-4Gy than the control group. 5. The total level of extracellular and intracellular LDH activity was decreased as increased amounts of radiation dose was applied.

• 생명과학회지
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• 제12권3호
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• pp.363-368
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• 2002

한국 민속주의 품질평가를 위해 민속주 31종을 대상으로 에탄을 함량, pH, 산도, 총당 및 환원당의 함량과 같은 특성을 조사하였다. 또한 민속주의 ATP함량은 lumitester로 측정하여 생균수와 비전하였다. 민속주의 물리.화학적 특성은 아래와 같이 확인되었다.; pH는 3.59~4.79 였고 총 산도는 4.23~16.21이였으며 총당과 환원당의 함량은 각각 0.04 ~1.13, 0.006 ~ 0.999 g/100 mL로 나타났고 ATP함량은 $10^1$~$10^{6}$ RLU범위에서 관찰되었다.

• 한국식품과학회지
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• 제41권6호
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• pp.652-656
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• 2009

탁주를 효과적으로 살균하기 위해서 110가닥의 테프론 튜브와 9개의 자외선(UV) 램프(1,335W)로 구성된 허니컴방식의 UV 살균기를 제작하고 탁주를 순환시켜 살균하여 미생물 살균효과 및 저장 중의 품질변화를 평가하였다. 허니컴방식의 UV 살균기에서 유속 2 L/min에서 4분 동안 탁주를 순환시킨 조건은, 일반세균 및 진균을 2-3 log cycle 감소시키면서 관능적으로 양호한 품질을 얻을 수 있는 최적의 살균조건으로 판단되었다. 이 조건에서 살균 처리한 탁주를 $30^{\circ}C$에서 8일간 저장하면서 pH, 아미노태질소 함량, 환원당 함량, 산도, 그리고 일반세균수 및 진균수의 변화를 측정하였다. pH, 산도, 아미노태 질소 함량은 저장 중에 생탁주와 UV 살균탁주에서 모두 증가하는 경향을 나타낸 반면 환원당 함량은 감소하는 경향을 나타내었다. 또한 생탁주와 UV살균탁주의 L, a, b 값은 저장 중에 매우 유사한 경향을 나타내었다. 저장 중에 UV 살균탁주의 진균은 생육이 억제되었으며 일반세균은 저장 4일째에 생탁주 수준에 도달하였다.

• 미생물학회지
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• 제37권3호
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• pp.234-238
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• 2001

배추김치와 부추김치의 발효양상을 비교하기 위해 $20^{\circ}C$와 $10^{\circ}C$로 나누어 발효과정 중의 총 균수, 젖산균 수, pH 및 총 당함량을 비교 분석하였다. $20^{\circ}C$에서 발효한 배추김치의 경우 총 균수와 Leuconastoc속과 Lactobacillus속 젖산균 모두 발효 초기인 2일째에 최대에 도달하다가 그 이후에는 점점 감소하였다. 그러나 $20^{\circ}C$에서 발효한 부추김치의 경우에는 Leucanostoc속은 발효 3일째에 최대에 도달한 후 점차 감소하였지만 Lactobacillus속은 발효 15일 이후까지 그 균수가 유지되었다. $10^{\circ}C$에서 발효한 경우에는 배추김치, 부추김치 모두 $20^{\circ}C$에서 발효한 경우보다 Leuconostoc속과 Lactobacillus 속의 균수가 서서히 중가하다가 감소하였다. pH 변화는 배추김치 경우에는 3일 후에 적숙기 김치의 pH인 4.2 부근에 도달한 후 발효 5일째에 3.5 까지 낮아져 그 후에도 계속 유지되었으나 부추김치의 경우에는 발효 10일째까지 적숙기 김치의 pH인 4.2 이상으로 유지되었다. $10^{\circ}C$의 경우 배추김치는 6일 후 pH 4.2 정도였으나 부추김치는 24일 후에도 pH 4.2 이상으로 유지하였다. 발효 기간에 따른 총 환원당의 함량은 배추김치와 부추김치 모두에서 발효초기부터 발효가 진행됨에 따라 계속적으로 감소하였지만 $10^{\circ}C$에서 발효한 부추김치의 경우에는 감소정도가 매우 완만하였다. 이상의 결과로부터 부추김치가 배추김치보다 젖산균의 종식이 더디어 배추김치에 비해 발효가 서서히 진행됨을 알았다.

• Food Science and Biotechnology
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• 제16권2호
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• pp.198-204
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• 2007

The objectives of this study were to determine the quality characteristics, antioxidant activity, and cytotoxicity of fermented ginseng wine at each fermentation step. In the first mash with and without ginseng, viable cell counts (total cell, lactic acid bacteria, and yeast) were maximum between 2 to 4 days of fermentation. At the beginning of fermentation, Brix and ethanol contents, and titratable acidity increased, while pH decreased rapidly. At 3 days of fermentation of the second mash with ginseng, the viable cell counts were similar to those without ginseng and then continually decreased. At the end of fermentation, the pH of the second mash with ginseng was 4.00, lower than the pH of the second mash without ginseng, which was 4.35. Alcohol contents of second mashes with and without ginseng were 12.2 and 11.8%, respectively. In the aging period of ginseng and rice wines, the pH, titratable acidity, Brix, and ethanol contents did not change markedly. The results of sensory evaluation showed that fermented ginseng wine had good flavor and high acceptability. In the 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity assay, fermented ginseng wine ($IC_{50}$: 0.394 mg/mL) showed higher antioxidant activity than fermented rice wine ($IC_{50}$: 0.884 mg/mL). The butanol fraction of fermented ginseng wine exhibited weak cytotoxic activity against P388 and HeLa cell lines.

• 한국미생물·생명공학회지
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• 제40권2호
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• pp.111-116
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• 2012

구기자-맥문동 막걸리의 미생물 분포와 최적 저장 기간을 확립하기 위하여 먼저 구기자-맥문동 막걸리를 제조한 후 $4^{\circ}C$와 $20^{\circ}C$에 저장하면서 효모, 총 세균 그리고 젖산균의 생균 수 변화를 조사하였다. 발효가 완료되어 $4^{\circ}C$에서 15일간 저장하는 동안 효모 수는 큰 변화가 없었다. 하지만 30일간 저장한 후에는 약 62%가 감소되었다. $20^{\circ}C$에서 수행한 저장 실험에서는 15일간 저장한 후 초기 효모균수의 87%가 감소하였으며 30일간 저장한 후에는 약 95.2%가 감소되었다. 구기자-맥문동 막걸리의 DGGE 분석에 의해 S. cerevisiae와 미동정의 Saccharomyces sp.가 동정되었는데 $20^{\circ}C$에서 저장하였을 때Saccharomyces sp.가 더 빨리 사멸하였다. 저장 기간 중 총 세균 수와 젖산균의 변화 양상은 유사하였다. $4^{\circ}C$에서 저장 하였을 때 저장 15일 시점에서 총 세균 수는 약 64%가 감소하였으나 그 이후 저장 30일까지 총 세균수의 변화는 크게 없었다. $20^{\circ}C$에서 저장하였을 경우에는 초기 세균 수가 저장 15일 시점에서 총 세균수의 약 95%가 감소하였으며 그 이후 저장 30일 시점까지 총 세균수는 크게 변화하지 않았다. DGGE분석을 통해 발효 개시 시점에서는 W. cibaria가 우점균이었다가 점차 L. fermentum과 P. acidilactici가 증가하여 저장 기간 동안 이들이 우점균으로 존재 함을 확인하였다.

• 한국식품영양학회지
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• 제21권3호
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• pp.288-292
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• 2008

To save cost and time in Kimchi manufacture, the use of raw red-pepper paste and device-mashed vice materials, in place of dried red-pepper powder, was examined. Two kinds of Kimchi were prepared: One with dried red pepper powder and device-not mashed vice materials and the other with raw red pepper paste and device-mashed vice materials. Then pH, total acidity, total viable cell counts, total lactic acid bacteria and sensory characteristics were evaluated. Comparisons of the two Kimchis, indicated that changes in pH, total acidity, the total number of viable cells and total lactic acid bacteria were similar between the two groups. The acceptability score of the Kimchi made using the raw red pepper paste and device-mashed vice materials was slightly lower than that of Kimchi made using the dried red-pepper powder. This color was indistinctly changed since the vice materials were mashed and mixed. In conclusion, the results indicate that when manufacturing Kimchi using device-mashed vice materials, Kimchi of better quality can be made by adding dried red-pepper powder.

• 한국환경보건학회지
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• 제34권5호
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• pp.387-394
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• 2008

The toxicity of methyl tert-butyl ether (MTBE), tert-butyl alcohol (TBA) and formaldehyde (FA) on the indigenous microbial community in forest soil was studied. MTBE, TBA and FA with different concentrations were added into microcosms containing forest soil samples. After 10 and 30 days, total viable cell number and dehydrogenase activity in the microcosms were evaluated. Bacterial communities in the microcosms were also analyzed using a denaturing gradient gel electrophoresis (DGGE). Dehydrogenase activity and total viable cell number were decreased according to the increase of MTBE, TBA and FA concentrations (P<0.05). FA toxicity was the highest, but TBA toxicity was the lowest. The results of principal component analysis using DGGE fingerprints showed that the microbial communities contaminated MTBE, TBA and FA were grouped by exposure time not exposure concentration. Dominant species in the microcosms were as follows: Photobacterium damselae sub sp. and Bacillus sp. KAR28 for MTBE; Mycobacterium sp. and Uncultured Clostridium sp. for TBA; and Uncultured Paenibacillaceae bacterium and Anxynobacillus, Flavithermus for FA.

• 한국식품조리과학회지
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• 제20권4호
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• pp.418-422
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• 2004

We investigated microbial populations of an upland and cultivated Codonopsis lanceolata. The microbial populations from both types of soils were also investigated. There were more than 10 microorganisms existed in upland than cultivated one. The total viable cell counts of C. lanceolata from upland and cultivated one, especially in the upper zone, were 9.7x10$\^$6/ CFU/g and 4.2${\times}$10$\^$6/ CFU/g, respectively. As a results, upper parts of C. lanceolata in upland were considered to harbour approximately more than 2.3 fold higher microorganisms than in cultivated one. However, the total viable cell counts between the two soil habitat, that is, 1.2${\times}$10$\^$7/ CFU/g from upland and 1.0x10$\^$7/ CFU/g from cultivated, were not significantly different. We also examined the unique flavor producing microorganisms in the soil extract broth including 25% C. lanceolata extract. One microorganism was detected in upper pars of C. lanceolata and upland soil. No. 6, microorganism causing the characteristic flavor of C. lanceolata was continued as Actinomyces by microscopy.