• KSBB Journal
• /
• 제18권4호
• /
• pp.249-254
• /
• 2003

Candida magnoliae M26에 의한 erythritol의 산업적 생산을 위한 산업용 질소원의 선정과 이를 이용한 유가식 배양에서의 erythritol 생산을 위한 최적 조건의 결정에 대한 실험을 수행하였다. 실험결과에서 산업용 질소원으로 가격이 가장 저렴하면서 erythritol의 수율과 생산성이 거의 yeast extract와 유사한 light steep water (LSW)를 선정하였다. 즉 선정한 LSW 43.3 mL/L과 glucose 250 g/L을 이용한 회분식 발효에서 52.6％의 수율과 0.52 g/L-hr의 생산성으로 131.6 g/L의 erythritol을 생산하였다. 생산성 향상을 위한 2단계 유가식 배양에서 고농도 균체를 얻기 위한 최적이 C/N ratio는 1.7으로서 glucose 100 g/L와 LSW 500 mL/L를 이용한 회분식 배양에서 71.0 g/L의 세포농도를 얻을 수 있었다. 배지의 초기 pH 조절방법에 대한 연구에서는 28％ 암모니아 용액으로 pH 6.5로 조절할 경우 erythritol의 수율은 감소하였으나 높은 생산성으로 erythritol을 얻을 수 있었다. 따라서 erythritol의 수율 향상을 위한 생산단계에서의 최적 glucose 농도는 450 g/L이 되도록 하는 경우이며, 이때에 37.3％의 수율과 1.66 g/L-hr의 생산성으로 185.5 g/L의 erythritol을 생산할 수 있었다. 따라서 산업용 질소원으로 선정된 LSW를 이용한 2단계 유가식 발효 공정을 통하여 회분식 배양과 비교해 볼 때 수율은 1.4배 정도 감소되었지만 erythritol의 생산성은 3.2배로 향상시킬 수 있었다.

• Applied Biological Chemistry
• /
• 제36권6호
• /
• pp.488-494
• /
• 1993

토양으로부터 생육도와 유기산의 자화도가 우수한 광합성세균 P17 균주를 분리하여 균학적 성질을 검토한 결과 이 균주는 Rhodospirillum rubrum으로 동정되었다. 유기폐수처리용 종균 생산을 위한 본 균주의 배양조건을 검토한 결과, 탄소원으로서 0.2% Na-acetate, 0.1% Na-propionate, 0.2% Na-lactate를 함유한 혼합 유기산이 효과적이었으며, 0.1% yeast extract를 첨가하였을 때 높은 생육도를 나타내었다. 최적배양조건의 환경인자들은 온도 $30^{\circ}C$, pH 7.0, 조도 2,500 lux, 교반 $50{\sim}100\;rpm$ 등이었다. Jar fermentor를 이용한 회분배양과 반연속배양으로부터 각각 5.17 g/l와 7.93 g/l의 균체가 생산되었으며, 연속배양에서는 희석비율 0.21 $h^{-1}$에서 생산성이 0.206 g/l/h이었다. R. rubrum P17을 두부공업폐수에 적용시켰을 때, 4일간 배양으로 초기 COD(3,240 mg/l)를 250 mg/l까지 감소시켰다.

• 환경생물
• /
• 제24권4호
• /
• pp.307-313
• /
• 2006

2004년 9월과 11월, 2005년 1월, 5월 및 8월의 총 5회에 걸쳐 대한민국 통영연안의 1개 정점에서 표층해수를 계절별로 채취하여 해양세균 군집을 분석하였다. 선택배지에서 순수분리하여 VITEK Microbe ID system으로 동정한 배양법과 16S rRNA PCR-DGGE로 분석한 결과를 상호비교하였다. 배양법에 의한 각 계절별 해양세균 군집의 종조성은 2004년 9월은 5종, 11월은 5종, 2005년 1월은 4종, 5월은 6종 및 8월은 10종으로 조사되었고, Pseudomonas fluorescens와 Acinetobacter lwoffii는 계절과 관계없이 모두 검출되었으며, 그 외에 Pseudomonas stutzeri, Sphingomonas paucimobilis 및 Burkholderia mallei 등이 동정되었다. 16S rRNA PCR-DGGE에 의한 군집분석 결과는 2004년 9월은 10개체군, 11월은 11개체군, 2005년 1월은 6개체군, 5월은 9개체군 및 8월에는 13개체군이 조사되었고, Acinetobacter lwoffii, Burkholderia mallei, Pseudomonas fluoresence, Actinobacillus ureae, Burkholderia sp., Pseudomonas stutzeri, Roseobacter sp., Vibrio parahaemolyticus, Sphingomonas paucimobilis 및 Rugeria algocolus 등이 동정되었다. 이로부터 해양세균 군집의 분포특성을 파악하는 데는 16S rRNA PCR-DGGE가 배양법보다 더 효율적임이 판명되었다.

• 한국작물학회지
• /
• 제41권6호
• /
• pp.650-655
• /
• 1996

일정세기 이상의 자력을 통과한 물(자화수)을 이용하여 벼 callus 유기 및 식물체 재분화 효율을 높이고자 팔공벼를 대상으로 시험한 결과를 요약하면 다음과 같다. 1. 벼 callus 유기효율은 자화수 처리한 도체, 액체배지에서 공히 이온수 처리보다 상대적으로 각각 30%, 16% 높았으며 절대빈도에서도 고체, 액체배지 각각 27.3%, 15.4%를 나타내어 일반적인 증류수 이용배지보다 대체로 높은 경향이었다 2. 식물체 재분화 효율에서도 자화수 처리한 고체배지에서 44.7%로 이온수 처리의 39.3%보다 5.4%높았으나, 액체배지의 경우 오히려 이온수의 재분화율이 다소 높았으나 유의성은 없었다. 3. 재분화된 식물체의 초기생육을 조사한 결과 자화수 처리가 이온수 처리보다 3일 후 50%, 7일 후 36%의 신장효과가 있었다. 4. 배지내 용존산소량을 측정한 결과, 자화수처리 배지에서 배양전 5.64ppm으로 이온수처리 배지보다 용존산소량이 18.9% 높았으나 배양 4 주후에는 자화수 및 이온수 처리 배지 각각 4.55ppm, 4.45ppm으로 비슷하였다. 5. 배지의 온도별 pH 변화를 조사한 결과 자화수 처리 배지의 pH가 이온수처리 pH보다 0.10～0.30정도 높았다. 6. 따라서 벼 ⇒allus 유기 및 식물체 재분화 효율을 높이는데 700 Gauss의 자력을 통과한 물(자화수)의 처리가 이온수 처리 보다 효과적이었으며 앞으로 좀더 정밀한 기초연구가 필요하다고 생각된다.

• 한국환경농학회지
• /
• 제41권3호
• /
• pp.191-198
• /
• 2022

BACKGROUND: Plants can be grown using a culture medium without soil using a hydroponic system. Crop production by the hydroponic system is likely to increase as a means of solving various problems in the agricultural sector such as aging of rural population and climate change. Different water sources can be used to prepare the culture medium used in the hydroponic system. Therefore, it is necessary to study the effect of different water sources on crop production by the hydroponic system in order to explore the applicability of various water resources. METHODS AND RESULTS: Lettuce was cultivated by the hydroponic system and three different water sources [tap water (TW), bottled water (BW), and groundwater (GW)] were used to compare the effect of water sources on lettuce growth. The three kinds of waters with a nutrient solution (TW-M, BW-M, GW-M) were also used as the media. After the six-week growth period, the lettuce length and weight, the number of leaves, and the contents of chlorophylls and polyphenols were compared among the different media used. The lettuces did not grow in the waters without the nutrient solution. In the media, the lettuce growth and the contents of chlorophylls were affected by the different water sources used to prepare the media, while the contents of polyphenols were not affected. The absorbed amounts of ions by lettuces, especially Ca and Zn ions, and the dry weight of the harvested lettuces showed a strong positive correlation. CONCLUSION(S): Overall, this study shows that different water sources used for growing lettuce in a hydroponic system can affect lettuce growth. Further studies on the enhancement of crop qualities using different water sources may be required in future studies.

• 복식문화연구
• /
• 제12권2호
• /
• pp.279-289
• /
• 2004

This study was conducted to compare the hunting reaction of finger in the cold water. Finger skin temperature is measured the left middle finger tip immersion in cold water of 5℃ for 30 minutes and measurements were made on finger skin temperature(Ts), thermal comfort, and cold pain sensations during the experiment at the spring (March) and Winter(December). Results were follows. Is before immersion was at the highest in spring and at the lowest in winter and was closely related to the indoor temperature Ts during immersion and recovery. Mean of finger skin temperature(MST), the skin temperature at the first rise(TTR) and amplitude of finger skin temperature reaction during immersion(AT) were significant higher in spring than that in winter(P＜.01). The lowest skin temperature(LST) during the cold water immersion were significantly higher in spring than that in winter (P＜.05). The frequency of the appearance of cold-Induced vase dilation(CIVD) was higher in spring than that in winter. However, time for the first temperature(TTR) and recovery time(RT) had no seasonal variation. In addition, cold pains during immersion were felt more strongly in spring than in winter. Local thermal sensation, finger thermal sensation in dynamic state during hand immersion was different from that in the Winter. Spring was slowly cold in cold water immersion.

• 한국농업기계학회:학술대회논문집
• /
• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
• /
• pp.584-590
• /
• 1993

The constructed closed recycling system discussed in this technical report will be economically viable in future for the production of fish and vegetable in earth, space station and space colony, further, it will contribute a lot in the prevention of pollution in the world's ecological system. To make combined system, water management (Nitrification) is required, and it took 45 days to breed microorganism which facilitates this process. After this period , the recycle was confirmed to be working .Using derived equations, the expected nutrient characteristics of waste water were determined and it was found that the resulting nutrient balance was almost same as that in hydroponic solution when KOH was added to maintain pH level. Reverse osmosis (RO) system could solve the problem of the low nutrient concentration . It was found that plants grow well in fish waste water which was produced using RO system. RO system could combine fish and plant production through the advantageous use of separated high concentration water for plant and permeated water for fish in integrated combined system.

• 한국식생활문화학회지
• /
• 제32권6호
• /
• pp.583-588
• /
• 2017

This study examined the antioxidant and neuronal cell protective effects of the water and methanol extracts of Eugenia caryophyllata Thunb. The total polyphenol content was significantly higher in the methanol extract than in the water extract. The DPPH radical scavenging activity in the water extract was similar to Vit. C at a concentration of $100{\sim}200{\mu}g/mL$. The ABTS radical scavenging activity in the water and methanol extract was similar to Vit. C at a concentration of $800{\sim}1,000{\mu}g/mL$. The superoxide dismutase (SOD)-like activity in the methanol extract was similar to Vit. C at a concentration of $800{\sim}1,000{\mu}g/mL$. The DPPH, ABTS radical scavenging and (SOD)-like activity increased with increasing extract concentration. In a cell viability using MTT, the water extract (50 and 100 ppm) and methanol extract (100 ppm) had a protective effect against $H_2O_2$-induced neurotoxicity.The result ssuggest that the extract of E. caryophyllata Thunb. has antioxidant activities and may be useful for treating neurodegenerative disorders.

• 한국식생활문화학회지
• /
• 제32권2호
• /
• pp.135-143
• /
• 2017

This study evaluated the quality characteristics of semi-dried noodles prepared with different water contents (wet noodles; 32, 24, 22, 20%, dry noodles; 12%). The drying process was carried out in a drying chamber at $13{\sim}18^{\circ}C$ temperature and 75~95% humidity. The proximate composition of Korean wheat flour was as follows: water $22.1{\pm}3.64%$, protein $8.6{\pm}0.13%$, fat $1.3{\pm}0.10%$, ash $0.7{\pm}0.02%$, carbohydrates $67.3{\pm}0.10%$. As water contents decreased, both L and b values significantly decreased before cooking of noodles, whereas L, a, and b values were not significantly different after cooking of noodles. Weight, water absorption, and volume of cooked noodles significantly increased as water content decreased, whereas turbidity of soup was not significantly different. Cutting hardness before cooking of noodles significantly increased as water content decreased. Sections of noodles after cooking by SEM (scanning electron microscopy) showed roughness and fewer round starch particles as water content decreased. For overall preferences according to the sensory evaluation, noodles prepared with different water contents were not significantly different. According to the results, semidried noodles have development potential to complement the disadvantages of both wet noodles and dry noodles.

• International Journal of Advanced Culture Technology
• /
• 제9권3호
• /
• pp.360-366
• /
• 2021

In this study, we tried to examine how the kinking of the fire hose affects the time taken for initial water discharge by measuring and analyzing the time taken for initial water discharge with different number of kinks at different locations of the hose. The average time taken for initial water discharge was obtained by measuring the time in the unkinked state of the fire hose. Based on this standard, we conducted the experiment by selecting the kinking locations in the hose near the water outlet and nozzle, and setting the number of kinks to 3, 6, 9, and 12. The results of this study are as follows: First, if the fire hose has 5 kinks or more near the nozzle, no water was released. Second, when comparing the case of no kinks and 4 kinks near the nozzle, there was no significant difference in the time taken for initial water discharge. Third, when the fire hose was kinked 10 times near the outlet, the time required for initial water discharge increased by 1.62 seconds on average compared to the case with no kinking, but there was no problem with water discharge. Lastly, regarding the kinking locations of the fire hose, it was found that the greater the number of kinks near the nozzle than near the outlet, the greater the effect on the discharge. As a result, it is concluded that it would be preferable to install non-kinking devices near the nozzle of the fire hose.