• 한국토양비료학회지
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• 제38권5호
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• pp.287-293
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• 2005

본 연구에서는 농업용 미생물제 수요의 증가에 따른 보다 안정한 미생물제 공급과 규격화된 품질 보증 및 미생물제 생산성 확대를 위하여 식품 산업에서 활용되고 있는 미생물제의 미세캡슐화 기술을 응용하여, 농업용 미생물제 캡슐화 소재선발 및 캡슐화 최적조건을 조사하고 생산된 미생물 캡슐제의 생균력과 안정성에 관하여 검토하였다. 본 실험의 캡슐화 장치는 extrusion 기법에서 주로 사용되고 있는 air atomizing device 대신 저속의 연동펌프를 이용한 micro-nozzle 방식을 설계하여 수행하였다. 농용 미생물의 캡슐화 소재선발을 위해 bead 형성이 용이하며 생균력을 안정적으로 유지할 수 있고 저렴한 비용으로 구입이 가능한 캡슐제를 조사한 결과 Na-alginate와 K-carragenan은 bead 형성이 우수하게 나타났으며 캡슐내 생균수는 $5.3-7.4{\times}10^7cfu\;g^{-1}$로 gellan gum과 locust bean gum 등에 비하여 6배 이상 높은 생균수를 나타냈다. Na-alginate의 경우 캡슐이 매우 단단하고 매끄러웠으며, K-carragenan보다 7배 이상 저렴한 것으로 조사되었다. 이상 농업용 미생물제의 캡슐화 소재로서 Na-alginate를 사용하는 것이 가장 효율적이고 경제적이라 판단되었다. 농업용 미생물제의 캡슐화를 위한 최적의 캡슐화 소재로 1.5% 농도의 Na-alginate에 1.0% starch와 같은 안정제를 혼합하여 사용할 경우 생균력을 유지하는 데 보다 안정적이었다. 최적조건에서 형성된 캡슐의 형태를 관찰한 결과 캡슐의 표면구조는 매끈하고 규칙 바른 구형을 나타내었으며, 내부 구조는 비교적 균일한 polymatrix를 형성하였 으며 부분적으로 큰 공극을 형성하였다. 미세 캡슐 내 미생물 생존력을 유지하기 위한 캡슐막의 효과를 나타낼 수 있는 안정제로 저렴한 가격으로 구입이 용이한 starch와 zeolite를 이용하여 생균력 증진효과를 검토하였다. 세균을 이용한 미생물 캡슐체의 경우 starch와 zeolite 모두 약 70-80% 생균력을 나타내었으며, 효모의 경우 starch를 안정제로 이용한 경우 67%의 생균력을 나타내었으나 zeolite를 안정제로 첨가한 경우 80% 이상의 높은 생균력 증진을 나타내었다. 이상의 결과로부터 미생물을 캡슐화 할 경우 무기재료인 zeolite를 첨가할 경우 장기간 생균력 안정성이 유지되는 것으로 나타났다.

• 한국식품저장유통학회지
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• 제6권4호
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• pp.442-447
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• 1999

섬유질이 풍부하고 enthocyanin색소가 풍부한 자색 고구마를 이용하기 위하여 탈지유와 설탕이 들어있는 기본배지에 증자, 박피한 고구마를 첨가한 후 5종(Lactebacillus bulgaricis, Lactobacillus delbruchii sub. sp. lactis, Streptococcus lactis, Bifidobacterium bifidum, Leuconostoc lactis) 의 젖산균주를 배양, 접종하여 호상 요쿠르트를 만들고 자색고구마가 젖산균의 생육과산 생성, 색도에 미치는 영향 및 저장성 등을 조사한 결과 L. bulgaricus균을 배양한 경우가 젖산균의 증식과 산 생성이 가장 빨라 발효개시 12시간만에 1.04 $\times$$10^{9}$CFU/$m\ell$의 생균수와 pH 4.22를 나타냈고 B. bifidum균은 발효개시 24시간까지는 젖산균의 증식이 느리게 이루어져 발효개시 36시간에 달할 때 3.3 $\times$ $10^{8}$ CFU/$m\ell$의 생균수와 pH 5.1을 나타냈다. 발효종료 후 자색고구마를 첨가한 요쿠르트의 자색은 B. bifdum균에 의한 요쿠르트제조시 색도가 가장 안정하였고 Leuc. lactis, L. delbruechii sub. sp. lactis, L bulgaricus순으로 안정하였으며 St. lactis균에 의한 요쿠르트는 자색의 색소 소실이 가장 많았다. 2~3$^{\circ}C$에서 저장시 저장 2주까지 pH의 변화는 거의 없었고 생균수의 변화는 L. bulgaricus와 L. delbruechii sub. sp. lactis균에 의해 제조된 요쿠르트는 저장 1주까지는 변화가 없었으나 그 이후는 약간 감소하였으며 St. lactis균과 B. bifidum 균은 저장 1주까지 저온에서도 생균수가 소량 증가함을 보여주었다. 색도는 저장 2주 후 B. bifidum균에 의한 요쿠르트 제조시 자색도가 많이 소실되었고 L. delbruechii sub. sp. lactis균에 의한 요쿠르트가 가장 안정하였다.

• 한국환경보건학회지
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• 제38권1호
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• pp.1-7
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• 2012

Carbon nanotubes (CNTs) stand at the frontier of nanotechnology and are destined to stimulate the next industrial revolution. Rapid increase in their production and use in the technology industry have led to concerns over the effects of CNT on human health and the environment. The prominent use of CNTs in biomedical applications also increases the possibility of human exposure, while properties such as their high aspect ratio (fiber-like shape) and large surface area raise safety concerns for human health if exposure does occur. It is crucial to develop viable alternatives to in vivo tests in order to evaluate the toxicity of engineered CNTs and develop validated experimental models capable of identifying CNTs' toxic effects and predicting their level of toxicity in the human respiratory system. Human lung epithelial cells serve as a barrier at the interface between the surrounding air and lung tissues in response to exogenous particles such as air-pollutants, including CNTs. Monolayer culture of the key individual cell types has provided abundant fundamental information on the response of these cells to external perturbations. However, such systems are limited by the absence of cell-cell interactions and their dynamic nature, which are both present in vivo. In this review, we suggested two viable alternatives to in vivo tests to evaluate the health risk of human exposure to CNTs.

• Journal of Microbiology and Biotechnology
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• 제23권12호
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• pp.1708-1716
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• 2013

Conventional molecular detection methods cannot distinguish between viable and dead Escherichia coli O157 cells. In this study, the loop-mediated isothermal amplification (LAMP) method combined with propidium monoazide (PMA) treatment was developed to selectively detect viable E. coli O157 cells. Four primers, including outer primers and inner primers, were specially designed for the recognition of six distinct sequences on the serogroups (O157) of the specific rfbE gene of the E. coli O157 genome. PMA selectively penetrated through the compromised cell membranes and intercalated into DNA. Amplification of DNA from dead cells was completely inhibited by $3.0{\mu}g/ml$ PMA, whereas the DNA derived from viable cells was amplified remarkably within 1 h by PMA-LAMP. Exhibiting high sensitivity and specificity, PMA-LAMP is a suitable method for evaluating the inactivation efficacy of slightly acidic electrolyzed water in broth. PMA-LAMP can selectively detect viable E. coli O157 cells. This study offers a novel molecular detection method to distinguish between viable and dead E. coli O157 cells.

• Biotechnology and Bioprocess Engineering:BBE
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• 제3권2호
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• pp.51-54
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• 1998

It has been proved that co-cultivation of human neroblastoma cells and human fibroblast cells can enhance nerve cell growth and the production of BDNF in perfusion cultivation. In batch co-cultivation, maximum cell density was increased up to 1.76${\times}$106 viable cells/mL from 9${\times}$105 viable cells/mL of only neuroblastoma cell culture. The growth of neuroblastoma cells was greatly improved by culturing both nerve and fibroblast cells in a perfusion process, maintaining 1.5${\times}$106 viable cells/mL, which was much higher than that form fed-batch cultivation. The nerve cell growth was greatly enhance in both fed-batch and perfusion cultivations while the growth of fibroblast cells was not. It strongly implies that the factors secreted from human fibrobast cells and/or the environments of co-culture system can enhance both cell growth and BDNF secretion. Specific BDNF production rate was not enhanced in co-cultures; however, the production period was increased as the cell growth was lengthened in the co-culture case. Competitive growth between nerve cells and fibroblast cells was not observed in all cases, showing no changes of fibroblast cell growth and only enhancement of the neuroblastoma cell growth and overall BDNF production. It was also found that the perfusion cultivation was the most appropriate process for cultivating two cell lines simultaneously in a bioreactor.

• 미생물학회지
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• 제42권3호
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• pp.205-209
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• 2006

호소수내의 '살아있는 세균'을 측정하기 위하여 quantitative direct viable count (qDVC) 방법을 적용하였다. qDVC방법에 적용되는 최적 glycine 농도는 2%였으며, '살아있는 세균'을 계수하는데 있어서 평판계수법, CTC법 보다는 qDVC 방법이 보다 효과적이라는 것을 확인하였다. qDVC방법으로 '살아있는 세균'을 측정한 결과 다른 두 방법보다 $2.4{\sim}6.0$배 높은 값이었다. 또한 qDVC방법은 '살아있는 세균'을 죽은 세포 또는 휴면세포와 쉽게 구별할 수 있었다.

• 한국식품위생안전성학회지
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• 제1권1호
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• pp.47-50
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• 1986

Sanitary condition for raw milk in Korea was investigated in this study. It is hoped that the information will be used for reference in future endeavors of study in the field of public health and food sanitation in Korea. The results were summerized as follows: 1) The viable cell counts of bacteria in raw milk were tend to be increased under the various atmospheric temperature, and the correlation coefficient between temperature and total viable cells was r=+0.921(p<0.01). 2) The correlation coefficient between methylene blue reduction time test and viable cell counts of bacteria in raw milk was r=-0.799(p<0.01). 3) The relationship between total solid rate(%) and milk fat rate(%) was highly significant level as r=+0.745(p<0.01). 4) Highly significant correlation coefficient was r= +0.945(p<0.01) between milk fat and protein rate in raw milk.

• Preventive Nutrition and Food Science
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• 제16권4호
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• pp.386-389
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• 2011

Previous studies have confirmed that fermented whey produced by Leuconostoc mesenteroides CJNU 0147 or Lactobacillus casei CJNU 0588 display bifidogenic growth stimulator (BGS) activity. The present study sought to determine if the strain itself can improve the growth of bifidobacteria in co-cultures. In reinforced clostridial medium (RCM), both strains stimulated the growth of a Bifidobacterium lactis strain during the exponential phase and also stimulated the growth during almost all growth phases in whey broth. Fermented whey containing viable Leu. mesenteroides CJNU 0147 and L. casei CJNU 0588 cells maintained viability of the B. lactis strain stored at $10^{\circ}C$ in MRS broth. Viable cell count of the B. lactis strain without the fermented whey was decreased to 5.6 log cfu/mL after 15 days, whereas that of the strain with the fermented whey was slightly increased to 7.1 log cfu/mL as compared with initial viable cell count of 6.9 log cfu/mL.

• Preventive Nutrition and Food Science
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• 제7권4호
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• pp.397-404
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• 2002

Soybean curd residue (SCR) was fermented by lactic acid bacteria, Lactobacillus rhamnosus LS and Entercoccus faecium LL, isolated from SCR. The pH, titratable acidify and viable cell counts were determined from the fermented SCR to evaluate the lactic acid production and growth of lactic acid bacteria. Optimal amounts of pretense enzyme and glucose, and ideal fermentation time for SCR fermentation were estimated by response surface methodology (RSM). Raw SCR fermented by indigenous microorganisms had 0.78 % titratable acidity, The acid production in SCR fermented by L. rhamnosus LS was greatly enhanced by the addition of glucose and lactose. However only glucose increased acid production by Ent. faecium LL. The proof test of SCR fermentation demonstrated that similar results for titratable acidity, tyrosine content and viable cell counts to that predicted could be obtained by the at optimized fermentation conditions. In the presence of 0.029 % (w/w) pretense enzyme and 0.9% (w/w) glucose, the SCR fermented by Ent. faecium LL showed 1.07% (w/v) of titratable acidity, 1.02 mg% tyrosine content and 2$\times$10$^{9}$ (cfu/g) of viable cell counts. With the SCR fortified with 0.033% pretense enzyme and 1.7% glucose, L. rhamnosus LS showed 1.8% (w/v) of titratable acidity, 0.92 mg% of tyrosine content and 2$\times$10$^{9}$ (cfu/g) of viable cell counts.

• Asian Journal of Atmospheric Environment
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• 제5권3호
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• pp.152-156
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• 2011

Viable bacteria on water-insoluble airborne particles were detected in the urban atmosphere of Kumamoto ($134^{\circ}45'E$, $32^{\circ}28'N$), Japan, in autumn 2008. Airborne particles were collected onto film-covered Cu meshes under clear weather conditions. The samples were stained by fluorescent stains, and then viewed and photographed with an epifluorescent microscope. Non-biological and bacterial parts in particles larger than 0.8 ${\mu}m$ were distinguished by their morphologies, fluorescent colors and fluorescent intensities. Bacterial viable statuses were discriminated according to cell membrane damage. In total, 2681 particles were investigated and it was found that 78 airborne particles were associated with bacteria. Viable bacteria were identified on 48 particles. A few particles carried multiple viable bacteria. These results provide the evidence that airborne particles act as carriers of viable bacteria in the atmosphere.