• 임산에너지
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• 제20권2호
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• pp.20-27
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• 2001

글루코스 생산을 위한 효과적인 방법을 개발하기 위해서 cellulase에 의한 현사시 나무의 효소가수분해를 실시하였다. 목재의 효소가수분해는 미생물이 생산한 효소를 사용하여 글루코스를 생산하는 반응이다. 이렇게 얻어진 글루코스는 발효에 의해 쉽게 에탄올로 변환시킬 수 있다. 에탄올은 아세톤이나 부탄올, 시트릭산 그리고 락틴산을 제조하는 원료물질이나 석유자원을 대체할 수 있는 대체에너지 자원이다. 셀룰로오스의 효소가수분해 기작은 endo-cellulase, exo-cellulase 그리고 β-D-glucosidase라는 세 개의 서로 다른 형태의 효소가 연속적인 반웅에 의해 일어난다고 설명되어지고 있다. 본 실험의 목적은 다양한 농도의 수산화나트륨으로 현사시나무를 전처리 하여 이러한 전처리가 셀룰로오스의 결정화도와 리그닌함량에 미치는 영향과 가수분해율과의 관계를 조사하였다.

• Journal of Korean Biological Nursing Science
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• 제4권2호
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• pp.127-137
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• 2002

The purpose of this study was to compare the hand disinfection effect of waterless alcohol gel hand washing agent with that of soap and water, 4% chlorhexidine gluconate, and 10% povidone-iodine. Hands of fourty subjects were artificially contaminated with Acinetobacter baumannii $5m{\ell}$ and randomly distributed to each hand washing methods. Samples were collected from gloved hand by glove juice sampling procedure. Mean log reduction after hand washing were compared with baseline values. Number of microorganisms were converted to log and tested by ANOVA in SPSSWIN 10.0. Mean log reduction of soap and water, alcohol gel, 4% chlorhexidine gluconate, 10% povidone-iodine were $2.76{\pm}0.62$, $2.97{\pm}0.56$, $4.66{\pm}1.70$, $4.60{\pm}0.91$, respectively. The bactericidal effect of alcohol gel was similar to that of soap and water, but the effect was much less than chlorhexidine gluconate and povidone-iodine(p<0.001). In terms of microorganism reduction, the efficacy of waterless alcohol gel was almost the same as soap and water hand washing. Further evaluation of the bactericidal effect of waterless alcohol gel is needed because waterless alcohol gel is simple, convenient, and non-irritating hand washing agent and also very effective in busy hospital environment.

• 한국유기농업학회지
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• 제8권3호
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• pp.121-130
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• 2000

사과 저장중에 발생하는 푸른곰팡이병원균에 대한 길항미생물을 찾기 위하여 자연계로부터 유용미생물을 분리하여 Penicillum expansum에 대한 길항력 검정과 동정하였다. 자연계로부터 얻은 3,000여종의 미생물중에서 푸른곰팡이병원균에 대하여 길항력이 우수한 미생물을 1차적으로 11종 선발하였으며, 이중에서 가장 길항력이 뛰어난 미생물을 치종적으로 KB22를 선발하였다. 길항력이 우수한 KB22의 형태적 성질, 배양적 특성 및 생리 생화학적 성질 등을 조사하여 비교 검토한 결과 Bacillus subtilis와 유사한 균으로 동정되었다. 분리한 길항균 Baillus subtilis KB22는 푸른곰팡이병에 대한 55.9%의 높은 생장억제력을 보였으며, 한천배지에서 Penicillum expansum 접종 후 길항균처리와 열처리한 길항균배양액을 처리하였을 때 각각90%와 15%이상 길항력을 보여주었다.

• 한국식품영양학회지
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• 제30권3호
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• pp.395-404
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• 2017

Probiotics may be defined as microbial agents that can benefit humans and have been used primarily by mankind in fermented foods. A representative of probiotics is lactic acid bacteria (LAB), which has received attention recently due to its perceived health benefits. We reviewed research papers about Bifidobacerium and Lactobacillus, which are two of the most known of the LAB. Bifidobacerium alleviates diarrhea from various causes by improving intestinal microflora, and it has been reported that it reduces Helicobacter pylori bacteria known as the cause of gastric ulcer and stomach cancer. Bifidobacerium has also reported to be effective on immunization and allergy, reduce blood cholesterol, cancer, lactose intolerance. Lactobacillus alleviates diarrhea but has not fully demonstrated its effectiveness relative to other health issues. Several lactic acid bacteria and yeast are expected to act as probiotics, so, in the future, more research on the health benefits of lactic acid bacteria is needed.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.290-292
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• 2004

Heavy metal contamination has been increased in aqueous environments near many industrial facilities, such as metal plating facilities, mining operations, and tanneries. The soils in the vicinity of many military bases are also reported to be contaminated and pose a risk of groundwater and surface water contamination with heavy metals. The biological removal of metals through bioaccumulation has distinct advantages over conventional methods; the process rarely produces undesirable or deleterious chemical byproducts, it is highly efficient, easy to operate and cost-effective in the treatment of large volumes of wastewater containing toxic heavy metals. In addition, a recent development of molecular biology shed light on the enhancing the microorganism's natural remediation capability as well as improving the current biological treatment. In this study, characteristics of the cell growth and heavy metal accumulation by Saccharomyces cerevisiae strains expressing phytochelatin syntahse (PCS) gene were studied in batch cultures. The AtCRFI gene was demonstrated to confer substantial increases in metal tolerance in yeast. PCS-expressing cells tolerated more Cd$^{2＋}$ than controls.

• 펄프종이기술
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• 제34권2호
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• pp.32-41
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• 2002

To prolong freshness and to reduce a decay rate of cut flowers during storage and distribution, a new packaging paper was developed with grapefruit seed extracts(GFSE) as a natural microorganism control agent. The GFSE was fractionated in order to identify antibiotic fractions by HPLC equipped with C18-reverse phase column chromatography. Among the active fractions, three ones were identified as 1-chloro-2-methyl-benzene (ο-toluene), N, N-dimethyl-benzenemethaneamine, and 1-〔2-(2-ethylethoxy)ethoxy〕-4-(1,1,3,3- tetra methyl)-benzene, while the other three remained unidentified. The GFSE-added paper displayed an effective inhibitory activity against putrefactive bacteria and fungi which were involved in the decay of flowers. Despite excellent antimicrobial acts of the GFSE-treated packaging paper, it was not possible to prevent the cut flowers from being dehydrated during storage, which led to the reduction of their fresh weight. However, additional treatment for giving water- repellency property to the GFSE-treated paper decreased a reduction rate of the fresh weight up to around 50% compared to the only GFSE-treated one.

• International Journal of Oral Biology
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• 제41권2호
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• pp.75-81
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• 2016

Human mouth environment is known to include a variety bacteria, including Streptococcus spp., Staphylococcus spp., Actinomyces spp., Lactobacillus spp., Candida spp., Enterobacteriaceae, et al. Human oral microorganisms can cause dental caries, gingivitis, periodontitis, respiratory tract infection, and cardiovascular disease. Thus, right denture cleaning is essential to oral and general human health. The aim of this study was to evaluate the bactericidal effect of a sodium dichloroisocyanurate-based effervescent tablet (Aos Denti Germ, Aos Company, Chungbuk, Korea) against oral microorganisms. A total of 5 species Streptococcus spp. (Streptococcus anginosus, Streptococcus mitis, Streptococcus mutans, Streptococcus oralis, and Streptococcus sobrinus), Actinomyces oris, Candida albicans, and Escherichia coli were used in this study. All strains were exposed to the distilled water prepared with effervescent tablet. After the exposure, the mixture of strains and effervescent tablet was inoculated onto blood agar or MacConkey agar plate and cultured at $36^{\circ}C$. All strains were killed immediately on exposure to effervescent tablet. The results suggested that effervescent tablet could be used as an effective denture cleanser for dental hygiene.

• KSBB Journal
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• 제23권1호
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• pp.54-58
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• 2008

수소는 연료전지와 같은 친환경적인 용도로 인해 미래의 에너지로서 주목받고 있는데, 생물학적인 발효법은 수소의 생산을 위한 유망한 방법이다. 본 연구에서는 Enterobacter aerogenes KCCM 40146을 대상으로 수소 생산을 최대로 하기 위한 배지의 조건을 최적화하였다. 그 결과, 0.5M potassium phosphate buffer pH 6.5에서 glucose 30 g/L일 때 수소의 누적 농도가 431 $m{\ell}$로 최대값을 얻을 수 있었다. 질소원으로 peptone과 tryptone을 넣은 배지가 수소의 생산 뿐 아니라 균주의 성장에 가장 효율적이었다 한편, 미생물의 성장속도조절이 수소의 효율적 생산을 위해 중요한 실험변수임을 알 수 있었다.

• Preventive Nutrition and Food Science
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• 제6권2호
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• pp.96-100
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• 2001

Mixtures prepared from whole milk with added skin milk powder(2.5%, w/v) and Angelica keiskei juice (1.5%, w/v) were fermented with lactic acid bacteria (single and mixed culture of Lactobacillus bulgaricus and Strpetococcus thermophilus) for 24 hours. The fermented mixtures (curd yogurt) were evaluated for acid production (pH and titratable acidity), cell numbers, viscosity, sensory property and keeping quality. Results indicated that the addition of Angelica keiskei stimulated the acid production by lactic acid bacteria. The number of viable cells reached 4.5~7.3$\times$10$^{9}$ CFU/mL for Angelica keiskei-added yogurts, while 3.3~5.1$\times$10$^{9}$ CFU/mL for control yogurts. Viscosity of Angelica keiskei-added yogurts was higher (3,609~3,854 centipoises) than that of control yogurts(3,346~3,700 centipoises). Of the microorganism tested, mixed culture of Lactobacillus bulgaricus and Streptococcus thermophilus was most effective in acid production. The overall sensory score showed that Angelica keiskei yogurt fermented with Streptococcus thermophilus was evaluated as good as control yogurt. When yogurts were stored at 4$^{\circ}C$ for 12 days, pH, titratable acidity and viable cells of lactic acid bacteria were not significantly changed(p<0.05).

• 한국물환경학회지
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• 제23권6호
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• pp.993-997
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• 2007

The upflow anaerobic sludge blanket (UASB) reactor can be effective for treating simple organic compounds containing high concentration of ammonia nitrogen. The chemical oxygen demand (COD) removal efficiency was about 80% at ammonia nitrogen concentration up to 6,000 mg-N/L. This result also showed that it would be possible to treat propionate effectively at free ammonia nitrogen concentration up to 724 mg-N/L if sufficient time was allowed for adaptation. However the specific methanogenic activity (SMA) of granule was lower than that of granule in the reactor with lower ammonia nitrogen concentration. At 8,000 mg-N/L, the inhibition of high ammonia concentration was observed with evidence of increase of the volatile suspended solids (VSS) concentration in the effluent. It might be ascribed to the decrease in the content of extracellular polymer (ECP), which resulted to the sloughing off of obligated proton-reducing acetogens and heterogenotrophic methanogens from the exterior of granular sludge. This caused a great portion of the finely sludge to be easily washed out. Therefore, failure to maintain the balance between these two groups of microorganism cause accumulation of the hydrogen partial pressure in the reactor, which could have inhibited the growth of acetate utilizing methanogens.