• 한국식생활문화학회지
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• 제34권3호
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• pp.361-368
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• 2019

The purpose of this study was to establish the best optimized extraction condition for the optimal development of fresh maca beverage using low temperature extraction and enzyme treatment. Low temperatures were applied to prevent heat-related nutritional loss during the extraction process. Best extraction conditions were investigated based on the ratio of maca to water, the ratio of enzymes, extraction temperature and time, and agitation. The optimal enzyme conditions were also examined after the treatment of cellulase:pectinase mixture to maintain the original color and flavor, as well as to increase the extraction yield. When cellulase:pectinase was 1:1, the extraction rate ranged from 77.84 to 79.29%. In addition, the best extraction rate was found when maca was mixed with twice volume of water and incubated at $45^{\circ}C$ ($84.05{\pm}0.32%$) with 90 rpm ($87.13{\pm}0.46%$) agitation for 3 hours ($84.73{\pm}0.29%$). Furthermore, sensory evaluation showed a high score in flavor, sweetness, and overall acceptability after adding 3% jujube concentrate into a fresh maca beverage.

• 한국식생활문화학회지
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• 제14권5호
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• pp.455-460
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• 1999

In order to establish the processing condition of salt-fermented liquefaction of sardine (Sardinops melanoslicta), effect of temperature, pH value, and concentration of salinity on crude enzyme activity of sardine viscera were investigated. The optimum temperature range of crude enzyme activity in sardine viscera was $45{\sim}50^{\circ}C$ and the optimum pH value of it was 9.8. According to the concentration of salinity increased the crude enzyme activity in sardine viscera decreased. The relationship between concentration of salinity (X) and the crude enzyme activity (Y) in sardine viscera is shown as follows; Y=-0.01363X+0.7676 (r=-0.88). For the purpose of processing conditions of rapid- and low salt-fermented liquefaction of sardine, changes of viable cell count, histamine content, and volatile basic nitrogen (VBN) in the chopped whole sardine with 8% NaCl during preheating process at $40^{\circ},\;45^{\circ}$ and $50^{\circ}C$ for 48 hrs were analyzed. During preheating, initial viable cell counts of chopped whole sardine were $10^{4-7}/g$, but they decreased $10^{1-5}/g$ after 48 hrs. Histamine contents during preheating process at $40^{\circ}\;and\;45^{\circ}C$ were gradually increased, whereas at $50^{\circ}C$ were almost the same level after 48 hrs. VBN contents were continuously increased during preheating, but preheating at $50^{\circ}C$ samples were lower level than that of $40^{\circ}\;and\;45^{\circ}C$ ones. For the purpose to accelerate the fermentation and liquefaction of chopped whole sardine, preheating at optimum temperature of crude enzyme activity for 48 hrs was useful processing method and the contents of viable cell count, histamine, and VBN were safety level for food sanitation.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.326-329
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• 2003

When an electrokinetic process is applied to a HOC-contaminated soil, hybrid types combined with soil flushing, chemical oxidation, and bioremediation are generally used. Especially when the electrokinetic process is combined with bioremediation, the hybrid technology can solve several limits of bioremediation such as low microbial mobility, low soil temperature, and shortage of nutrients in subsurface circumstance. Because microbial surface is charged negatively, the microorganism moves from cathode to anode under electrical field. In this study, mixed culture mainly-consisted by Pseudomonas sp. was applied to remediate pentadecane-contaminated kaolinite with particle size less than 300${\mu}{\textrm}{m}$. This remediation system was named ‘electrokinetic bioaugmentation’ and consisted of model aquifer, electrode reservoirs, bioreactor, power supply, and pump. The mixed culture above 0.5 of optical density in bioreactor was supplied to two reservoirs and penetrated soil when the electric current was applied. To enhance the removal efficiency, the optimal medium composition, electric current, and voltage were investigated.

• 생물환경조절학회지
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• 제7권1호
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• pp.71-77
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• 1998

본 실험은 배지의 종류 및 환경조건에 대하여 배지의 온도변화 특성을 분석하는 것을 목적으로 하였다. NFT DFT, 슬라브형 성형암면, 면상암면, 펄라이트 배지를 사용하는 순환식 양액재배시스템을 구축하였다. NFT와DFT시스템은 양액 및 재배조 내의 공기온도를 측정하였고, 고형배지는 배지온도를 측정 .비교하였다. NFT시스탬의 양액 공급유량을 3$\ell$/min, 5$\ell$/min로 할 때, 양액 온도는 주간에는 전자가 후자에 비하여 약 3t 정도 높게 나타났다. 재배조내의 공기온도도 동일한 경향을 보이며 약 2$^{\circ}C$ 정도 차이를 나타냈다. DFT 시스템의 수위를 0.8cm, 1.8cm로 할 때, 양액 온도는 주간에는 전자가 후자에 비하여 약 1-2$^{\circ}C$ 정도 높게 나타났다. 또한 재배조내의 공기 온도도 동일한 경향을 보였다. 펄라이트 배지는, 주간에 멀칭한 배지가 약 3$^{\circ}C$ 정도, 면상암면 배지도 약 3$^{\circ}C$ 정도 높게 나타났고, 슬라브형 암면배지는 주야간 멀칭한 배지가 1-4$^{\circ}C$정도 높게 나타났고. 특히 주간에 높은 온도상승을 나타냈다. 고형배지중에서 펄라이트 배지온도가 암면에 비교하여 상대적으로 야간은 낮고 주간이 높게 나타났다. 슬라브형 암면의 경우는 표면적 전체가 공기중에 노출되어 있기 때문에 다른 고형배지보다 주간의 온도상승이 크게 나타났다. 고형배지의 뿌리부분의 온도가 작물과 작물사이의 배지온도에 비하여 주간 약 3f정도 낮게 나타났으며, 야간의 경우는 거의 차이가 없었다.

• 한국수산과학회지
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• 제46권6호
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• pp.868-877
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• 2013

To understand the effects of marine environmental and meteorological parameters on laver Porphyra yezoensis production at Nakdong River Estuary, we analyzed marine environmental (water temperature, salinity, nutrients, etc.) and meteorological properties (air temperature, wind speed, precipitation, sunshine hours) with yearly and monthly variations in laver production over 10 years (2003-2013). Air and water temperature, wind speed, sunshine hours and precipitation were major factors affecting yearly variability in laver production at the Nakdong River Estuary. Lower air and water temperatures together with higher levels of nutrients and sunshine and stronger wind speeds resulted in higher laver harvests. Salinity and nitrogen did not show clear correlations with laver production, mainly due to the plentiful supply of nitrogen from river discharge and the low frequency of environmental measurements, which resulted in low statistical confidence. However, environmental factors affecting monthly laver production were related to the life cycle (culturing stage) of Porphyra yezoensis and were somewhat different from factors affecting annual laver production. In November, a young laver needs lower water temperatures for rapid growth, while a mature laver needs much stronger winds and more sunshine, as well as lower temperatures for massive production and effective photosynthesis, mostly in December and January. However, in spring (March), more stable environments with fewer fluctuations in air temperature are needed to sustain the production of newly deployed culture-nets ($2^{nd}$ time culture). These results indicate that rapid changes in weather and marine environments caused by global climate change will negatively affect laver production and, thus, to sustain the yield of and predict future variability in laver production at the Nakdong River estuary, environmental variation around laver culturing farms needs to be monitored with high resolution in space and time.

• 한국양식학회지
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• 제21권1호
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• pp.41-46
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• 2008

본 연구의 목적은 rotifer Brachionus rotundiformis의 수온과 염분농도의 변화에 따른 이들의 소화효소 활성을 파악하고, 소화효소 활성을 기초로 적정 영양강화 조건을 찾는 것이다. 다른 온도에서 24시간 배양된 rotifer 밀도는 $32^{\circ}C$에서 1,453 개체/mL로 가장 높았다(P<0.05). 그리고 배양온도 $28^{\circ}C$에서 염분농도에 따른 rotifer 밀도는 15 에서 2,147 개체/mL로 가장 높게 나타났다(P<0.05). 배양환경에 따른 rotifer의 소화효소 활성에서 TAP 개체당 활성은 $24-32^{\circ}C$에서 유의적으로 높게 나타났으며(P<0.05), 단백질 비활성은 $32-36^{\circ}C$에서 높게 조사되었다(P<0.05). 그리고 TG-lipase 활성에서는 개체당 활성과 단백질 비활성 모두 $20^{\circ}C$에서 가장 높은 활성을 보였다(P<0.05). 또한 염분별 실험에서 TAP와 TG-lipase 활성은 32 psu에서 가장 높은 활성을 보였다(P<0.05). 32 psu에서 온도별 영양강화한 rotifer의 methionine 함량(% in protein), 지질 함량과 지방산 불포화도이 $20^{\circ}C$에서 유의적으로 높게 나타났다. 특히, DHA와 DHA/EPA 비가 $20^{\circ}C$ 실험구에서 12.6%와 12.5의 비로 각각 높았다(P<0.05). 따라서 rotifer B. rotundiformis의 지질 영양강화는 특히 TGlipase 활성을 높여 줄 수 있는 32 psu, $20^{\circ}C$에서 실시하는 것이 지방산 불포화도, DHA 및 DHA/EPA 비를 높여 줄 수 있는 효과적인 방법이라고 판단된다.

• Journal of Microbiology and Biotechnology
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• 제8권1호
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• pp.53-60
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• 1998

This study examines the effect of pH, temperature, metal ion concentration and culture density on metal biosorption by the nuisance cyanobacterium Microcystis aeruginosa. Ni biosorption was higher at pH 9.2 than at neutral and acidic pH. In contrast the biosorption of Cu and Zn was maximum at pH 7.0. However, biosorption of Zn was difficult to measure at pH values 9.2 and 10.5, owing to the formation of insoluble complexes. All the test metals (Cu, Zn, and Ni) showed maximum biosorption rate at low culture densities of 40 mg dry wt $1^{-1}$. The biosorption of Cu, Zn, and Ni was maximum at $40^{\circ}C$. However, no worthwhile difference in Zn and Ni sorption was noticed at 4 and $29^{\circ}C$ as compared to $40^{\circ}C$. Of these three metals used Microcystis showed a greater binding capacity ($K_{f}$ value=0.84, Freundlich adsorbent capacity) and accelerated biosorption rate for Cu under various environmental conditions. Fitness of mathematical models on metal biosorption by Microcystis confirmed that the biological materials behave in the same way as physical materials. These results suggest that before using a biosorbent for metal recovery, the environmental requirements of the biosorbent must be ascertained.

• 한국응용과학기술학회지
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• 제38권1호
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• pp.186-195
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• 2021

In this study, when stem cell culture solution is used as a cosmetic ingredient, one of the most prominent problems is that the ingredients generally have low thermal stability. Therefore, in this study, in order to find out how the stem cell culture medium is heated or preserved at high temperature, the effect of various effects of stem cells on the various effects of the stem cells was investigated. Investigated. As a result of the experiment, the wound healing assay confirmed that the cell migration increased after 6 hours, and after 24 hours, it was confirmed that the cell mobility was increased and cell division was promoted, thereby being concentrated. As a result of investigating the amount of transdermal water loss by preparing a cosmetic product containing stem cell culture solution, it was confirmed that the culture solution addition group showed an improvement rate of 31% compared to the non-added group, thereby helping in skin wound recovery. As a result of this, it is considered that this point should be considered when the stem cell culture medium is used as an active ingredient in cosmetics in the future.

• ALGAE
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• 제25권2호
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• pp.99-104
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• 2010

A psychrotolerant cyanobacterium, Nodularia spumigena KNUA005, was isolated from a cyanobacterial bloom sample collected near Dasan Station in Ny-${\AA}lesund$, Svalbard Islands during the Arctic summer season. To generate an axenic culture, the isolate was subjected to three purification steps: centrifugation, antibiotic treatment and streaking. The broad antibacterial spectrum of imipenem killed a wide range of heterotrophic bacteria, while the cyanobacterium was capable of enduring both antibiotics, the remaining contaminants that survived after treatment with imipenem were eliminated by the application of an aminoglycoside antibiotic, kanamycin. Physical separation by centrifugation and streaking techniques also aided axenic culture production. According to the cold-tolerance test, this mat-forming cyanobacterium was able to proliferate at low temperatures ranging between 15 and $20^{\circ}C$ which indicates the presence of cold-tolerance related genes in N. spumigena KNUA005. This suggests the possibility of incorporating cold-resistance genes into indigenous cyanobacterial strains for the consistent production of algae-based biofuel during the low-temperature seasons. Therefore, it is needed to determine the cold-tolerance mechanisms in the Arctic cyanobacterium in the next research stage.

• 한국식생활문화학회지
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• 제17권2호
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• pp.197-213
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• 2002

In order to establish the processing condition of rapid- and low salt-fermented liquefaction of anchovy (Engrulis japonica), effect of temperature on crude enzyme activity of anchovy viscera, pretreatment conditions, and the minimum content of adding NaCl were investigated. The minimum limitation of NaCl content for anchovy liquefaction was 10%. Sample A(water adding, heating, adding 10% NaCl): chopped whole anchovy adding 20% water and then heating for 9 hrs at $50^{\circ}C$ and then adding 10% NaCl and then fermented at room temperature$(8-29^{\circ}C)$ for 180 days. Sample B(water adding, heating, adding 13% NaCl): chopped whole anchovy adding 20% water and then heating for 9 hrs at $50^{\circ}C$ and then adding 13% NaCl and then fermented at room temperature for 180 days. Sample C(adding 13% NaCl): chopped whole anchovy and then adding 13% NaCl and then fermented at room temperature for 180 days. Sample D(adding 17% NaCl): whole anchovy adding 17% NaCl and then fermented at room temperature for 180 days. The content of free amino acids such as aspartic acid, serine and threonine fluctuated severely according to the pretreatment methods. Possibly they might be recommend quality indices of standardization for salt-fermented liquefaction of anchovy. As for the relation between fermentation period(X) and individual free amino acid(Y), five kinds of free amino acids such as glutamic acid, valine, glycine, lysine, and alanine showed highly significant in their coefficient of determination in most of samples. They might be recommend as quality indices for salt-fermented liquefaction of anchovy during fermentation. The difference of taste between products of the rapid- and low salt-fermented liquefaction and the traditional salt-fermented liquefaction were caused by their composition of the free amino acids ratios, in which were umami, sweet, and bitter taste in the extracts of anchovy during fermentation. The appropriate fermentation period of the sample A was shorten 30 days than the sample B and 60 days than the samples C and 90 days than the sample D in the processing of anchovy.