• Mycobiology
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• 제34권2호
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• pp.83-91
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• 2006

Characteristic growth patterns of Cordyceps militaris isolates on various media, under varying light conditions and at varying incubation periods were examined. Light was found to be the most critical single factor in determining the density, texture, and pigmentation of the mycelial culture of the fungus. However, under the light condition, the degree of pigmentation and mycelial density were found to be affected by the incubation period and type of medium. Irrespective of the variations in medium type or incubation period, there was no pigmentation of the mycelium under dark condition. Radial growth of the mycelium was faster under dark incubation rather than under light incubation. Abundant mycelial density and darkest pigmentation of C. militaris isolates were produced in nutritionally rich media like SDAY, SMAY and CZYA, suggesting that these media may fulfill all the requirements for vegetative growth of the fungus. Growth characteristics of C. militaris isolates could be easily observed by the simple agar culture method, which would be useful to characterize the phenotypic characteristics of large number of pure cultures of the fungus under given conditions of growth factors such as medium, light and temperature.

• 한국식품과학회지
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• 제28권3호
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• pp.405-410
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• 1996

항암, 시력 회복, 변비 , 당뇨병 , 신장병 , 불면증 등에 치료 호과가 있어 건강 음료로 이용되고 있는 tea fungus 발효 홍차를 당의 종류(자당, 포도당, 과당, 옥수수물엿), 농도(10-60% w/v), 그리고 배양 온도별($5-50^{\circ}C$)로 제조하여 발효액의 pH변화와 산생산성을 보았다. 자당과 포도당을 첨가하여 제조한 홍차 용액 중에서 산생성 경향이 서로 유사하고, 자당과 옥수수물엿을 사용한 홍차 용액에서 산생성 경향이 서로 유사한 것으로 보아 자당보다 과당의 이용성이 높은것으로 추정된다. 배양액 표면의 막 형성과 생육, 그리고 생성을 위한 최적 온도는 $30^{\circ}C$였다. 20%이상의 자당과 과당을 사용한 홍차 용액을 $30^{\circ}C$에서 14일간 배양하였을 때 0.1-0.2%의 낮은 산 생성을 보였으며, 10%의 자당과 과당을 사용한 홍차 용액에서 14일간 배양시킨 발효 홍차의 total acidity는 각각 1.8% w/v(자당)과 0.68% w/v(과당)가 되었다. 발효 홍차의 pH는 배양 2일 후부터 당의 증류, 농도, 배양 온도에 크게 영향을 받지 않고 모든 배양액에서 2.74-3.56으로 떨어져 배양 14일까지 같은 수준의 pH를 유지하였다.

• Environmental Engineering Research
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• 제22권4호
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• pp.347-355
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• 2017

This study investigated how the combined changes in environmental conditions and nitrogen (N) deposition influence the mineralization processes and carbon (C) dynamics of wetland soil. For this objective, we conducted a growth chamber experiment to examine the effects of combined changes in environmental conditions and N deposition on the anaerobic decomposition of organic carbon and the emission of greenhouse gases from wetland soil. A chamber with elevated $CO_2$ and temperature showed almost twice the reduction of total decomposition rate compared to the chamber with ambient atmospheric conditions. In addition, $CO_2$ fluxes decreased during the incubation under the conditions of ambient $CO_2$ and temperature. The decrease in anaerobic microbial metabolism resulted from the presence of vegetation, which influences the litter quality of soils. This can be supported by the increase in C/N ratio over the experimental duration. Principle component analysis results demonstrated the opposite locations of loadings for the cases at the initial time and after three months of incubation, which indicates a reduction in the decomposition rate and an increasing C/N ratio during the incubation. From the distribution between the decomposition rate and gas fluxes, we concluded that anaerobic decomposition rates do not have a significantly positive relationship with the fluxes of greenhouse gas emissions from the soil.

• 한국작물학회지
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• 제44권2호
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• pp.102-105
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• 1999

Mineralization of organic N is an important factor in determining the appropriate rate of organic matter application to paddy fields. A kinetic analysis was conducted for nitrogen mineralization of rice, barley, Chinese milk Ovetch (Astragalus sinicus L.; MV) and narrow leaf vetch straw in paddy soil. Nitrogen immobilization occurred rapidly and its rate increased in straw with high C/N ratio. The amount of nitrogen mineralization was rapid in the first year of rice-vetch cropping system. The rate constant (K) depended on the C/N ratio of organic matter. Mineralization of straw increased at high temperature. The amount of available N increment resulted in fast mineralization of straw, especially in rice and barley straw. Chinese milk vetch had the greatest mineralization rate at all temperatures and fertilization levels followed by narrow-leaf vetch. However, rice and barley straws with high C/N ratio immobilized the soil N at the initial incubation duration. Chinese milk vetch or narrow leaf vetch was not effectively mineralized in mixed treatments with rice or barley straw. The mineralization rate of organic matter was mostly affected by the C/N ratio of straw and temperature of incubation. Organic matter with low C/N ratio should be recommended to avoid the immobilization of soil N and the increasing mineralization rate of straw.

• Environmental Analysis Health and Toxicology
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• 제26권
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• pp.1.1-1.6
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• 2011

Plasmodium vivax malaria has occurred annually in the Republic of Korea (ROK) since its re-emergence in 1993. P. vivax malaria in ROK has been strongly influenced by infected mosquitoes originating from the Democratic People's Republic of Korea. Korean P. vivax malaria has shown typical characteristics of unstable malaria transmitted only during the summer season, and displays short and long incubation periods. The changing pattern of the transmission period can be predicted by analyzing the seasonal characteristics of early primary attack cases with a short incubation period. Such cases began to gradually occur earlier in the 1990s after the re-emergence. Most of the malaria cases after mid-August are presumed to be early primary attack, short incubation period cases. Only primary transmission was possible until the early 2000s, whereas up to fourth or fifth transmission occurred in the mid-2000s. The results indicate that the length of transmission period has been gradually extending, which may be ascribed to a climate change-mediated temperature rise. Malaria and climate data should be integrated to analyze and predict the influence of climate change on malaria occurrence in ROK.

• 한국미생물·생명공학회지
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• 제10권2호
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• pp.87-93
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• 1982

Mucor plumbeus FRI 0007 균주의 배양조건에 따른 균체생산량 및 지방질의 생산량을 검토한 결과 온도는 37$^{\circ}C$, pH3.5에서 정치배양 하는 것이 최적조건이며, 25일간 배양했을때 균체량은 2.39g/50$m\ell$, 지방질의 함량은 50.73% 이었다. 균체량과 지방질의 함량은 온도가 증가할수록, pH가 낮을수록 증가하였으나 진탕배양의 경우 균체량은 감소하나 지방질의 함량은 증가되었다. 트리-글리세리드의 함량은 pH가 낮을때, 그리고 진탕배양을 했을때 그 함량이 높았다. 지방산의 조성은 온도, 질소원와 종류 및 진탕에 의한 영향을 받았으며 온도가 낮을때 그리고 진탕을 했을때 포화도가 낮았다. 지방질을 구성하고 있는 모노-글리세리드와 디-글리세리드는 팔미트산과 올레산으로 트리-글리세리드는 주로 팔미트산, 올레산 및 리놀레산으로 결합되어 있으며 포화도는 모노-글리세리드가 가장 높았다.

• Fisheries and Aquatic Sciences
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• 제21권9호
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• pp.23.1-23.8
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• 2018

Background: Russian sturgeon (Acipenser gueldenstaedtii) is an emerging candidate species in the Korean aquaculture domain owing to its highly valued caviar. Although the embryonic development of this species was previously described, the complete image data on the morphological differentiation of developing embryos have not been yet fully available. Further, with the viewpoint of larval production in hatchery, the effects of temperature on embryonic viability and the temporal window of hatching event have not been extensively studied. Hence, the objective of this study was to provide a complete set of photographic image data on the embryogenesis and also to examine the effects of incubation temperatures on embryonic viability and hatching event in farm-bred Russian sturgeon. Results: Typical characteristics of embryonic development including uneven, holoblastic cleavages with unequal blastomeres, followed by the formation of germ layer, neurulation, and organogenesis until hatching, were documented. Under different temperature conditions (12, 16, or $20^{\circ}C$), viability of embryos incubated at $12^{\circ}C$ was significantly lower as relative to those of 16 and $20^{\circ}C$ incubated embryos. Hatchability of embryos was higher, and the timing of hatching event was more synchronized at $20^{\circ}C$ than at 12 and $16^{\circ}C$. Conclusion: Data from this study suggest that the incubation of Russian sturgeon embryos at $20^{\circ}C$ would be desirable in the hatchery practice with respect to the good hatchability of embryos and the synchronization of hatching events. Additionally, the updated image data for complete embryonic development could be a useful reference guide for not only developmental researches but also artificial propagation of Russian sturgeon in farms.

• 한국토양비료학회지
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• 제49권5호
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• pp.510-516
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• 2016

Soil respiration has been recognized as a key factor of the change of organic matter and fertility due to the carbon and nitrogen mineralization. In this study, we evaluated the effect of soil respiration on the light fraction-C and inorganic N content depending on temperature in soil applied with organic matter. Soil respiration was calculated by using total $CO_2$ flux released from soil applied with $2Mg\;ha^{-1}$ of rice straw compost and rye for 8 weeks incubation at 15, 25, $35^{\circ}C$ under incubation test. After incubation test, light fraction and inorganic N content were investigated. Rye application dramatically increased soil respiration with increasing temperature. $Q_{10}$ value of rye application was 1.69, which was higher 27% than that of rice straw compost application. Light-C and $NO_3-N$ contents were negatively correlated to soil respiration. Light-C in rye application more decreased than that in rice straw compost with temperature levels. These results indicate that temperature sensitivity of soil respiration could affect soil organic mater content and N availability in soil due to carbon availability. Also, light fraction would be useful indicator to evaluate decomposition rate of organic matter in soil under a short-term test.

• Asian-Australasian Journal of Animal Sciences
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• 제22권5호
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• pp.626-635
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• 2009

An experiment was conducted to investigate the effect of Butylated Hydroxy Anisole (BHA), Butylated Hydroxy Toluene (BHT), Pentoxifylline (PTX), Theophylline (TPY) and Theobromine (TBR) on cold protection ability of Murrah buffalo semen at room ($22-25^{\circ}C$) and refrigerated temperature ($4-7^{\circ}C$). Each semen sample was divided into six parts of equal volume and sperm concentration; the first was kept as a control and the remaining five were treated with BHA, BHT, PTX, TPY or TBR. Sperm motility, abnormal spermatozoa, live-dead count, hypo-osmotic swelling and acrosomal integrity were studied at room and refrigerated temperature for various incubation periods viz.; 0, 4, 8, 12 and 24 h at room and 0, 12, 24, 36, 48, 60 and 72 h at refrigerated temperature. Significant improvement in sperm motility, live-dead count, hypo-osmotic swelling and acrosomal integrity were observed in BHT, PTX and TPY fortified extender at room and refrigerated temperature for various incubation periods. From the present study it could be concluded that cold protection ability of buffalo semen can be improved through the addition of BHT followed by PTX and TPY.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.261-263
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• 2008

We attempted modulation of the hydrogen dilution ratio in a Cat-CVD system to achieve both the minimal incubation layer and the high throughput. We obtained the incubation layer thickness of 3 nm, and were able to grow a 200 nm-thick film having a 70 % crystallinity in 18 minutes.