• Title/Summary/Keyword: Continuous cultures

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Effect of Light on the Sclerotial Formation of Sclerotinia sclerotiorum(Lib.) de Bary (균핵병균(Sclerotinia sclerotiorum(Lib.) de Bary)의 균핵형성에 미치는 광선의 영향)

  • Kim Ki Chung
    • Korean journal of applied entomology
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    • v.15 no.3 s.28
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    • pp.153-159
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    • 1976
  • Present paper was attempted to investigate the effects of the light on the sclerotium formation of some isolates of Sclerotinia sclerotiorum(Lib.) do Bary from lettuce, cucumber and rape. The investigations were performed in the both aspects inducing sclerotial primordia from the mycelial colony and developing such primordia. The cultures were grown on potato-dextrose agar and were treated with day-light fluorescent lamps. In the continuous light illumination for 21 days, numbers of sclerotial primordia and matured sclerotia were increased with increasing the light intensity up to about 500 Lux, but on the contrary the dry-weight of matured sclerotia was decreased. In the 800 Lux illumination, induction of the primordia was extremely depressed, and then matured sclerotia were almost not produced. Short-time illumination for 48 hours, although the light intensity was as high as 5000 Lux, increased the numbers of sclerotial primordia and matured sclerotia. Dry-weight of matured sclerotia, however, was slightly increased only at low intensity of 160 Lux. On the other hand, the light shock which u·as alternatively on-of light every one minute for 48 hours increased the number and dry-weight of sclerotia produced, but the former was more effective at 500 Lux shock and the later more effective at 160 Lux shock.

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The relationship between emotional intelligence and cultural competency of dental hygiene students (치위생(학)과 학생의 감성지능과 문화 역량과의 관련성)

  • Park, Min-Seon;Jang, Jong-Hwa
    • Journal of Korean society of Dental Hygiene
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    • v.18 no.3
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    • pp.385-397
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    • 2018
  • Objectives: The study was a cross-sectional research to examine dental hygiene students' multi-cultural experiences, emotional intelligence and cultural competency and to understand the correlations among them. Methods: The study was conducted from September $1^{st}$ to October $31^{st}$ 2016, based on the survey of 449 students in the department of dental hygiene at 7 Universities. The questionnaire consisted of 57 questions including general characteristics (n=7), multi-cultural experiences (n=7), emotional intelligence (n=16) and cultural competency (n=27). Results: Each score of students' emotional intelligence and cultural competency is 3.43 and 3.01 respectively in 5-point scale. An analysis of correlations between emotional intelligence and cultural competency shows that the higher the emotional intelligence, the higher the cultural competency (r=0.342). The factors affecting the cultural competency include use of emotions (${\beta}=0.327$, p<0.001), control of emotions (${\beta}=0.254$, p=0.001), frequency of multi-cultural media (${\beta}=0.221$, p<0.001) and experience of multi-cultural class (${\beta}=0.221$, p=0.002). The modified explanatory power in this model is 28.2% (F=10.856, p<0.001). Conclusions: There was a positive correlation between emotional intelligence and cultural competency, and the contacts with multi-culture and experience of class are identified as the affecting factors. Dental hygiene students should acquire theoretical experiences regarding the multi-culture through curriculum or continuous educations and it is necessary to promote such educations in order to develop and apply the programs for the enhancement of emotional intelligence.

A case Study about the Need of Identity and Components in Order to Effectively Regenerate Backward Alley (낙후된 골목의 효과적인 재생을 위한 정체성의 필요성과 구성요소에 관한 사례연구)

  • Park, Kun-Woo
    • Korean Institute of Interior Design Journal
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    • v.26 no.3
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    • pp.3-12
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    • 2017
  • From the stages of formation, to the processes of change, the alleys with long history not only reflect on the trends of the area, but also have a historical and cultural value as a place where the local residents make living and socialize. However, due to the rapid growth of the city's civilization, and industrialization, there has been a great amount of loss in the roles of the rural areas while urban areas have been expanding over time. The rural areas including the old alleys have been neglected and fell far behind in the processes of growth overall, and therefore, it became harder to trace the old days as well as the old emotion that we used to see. Nowadays, there are various cases in terms of alley regeneration project as people are getting more interested in it. The alley regeneration projects can be divided into two different backgrounds; a part of urban regeneration project by the government and local organizations and the other developed by the trends. This research, with successful case studies, is for analyzing the direction of the ultimate goal and the identity that only the alleys have. As the alleys contain history, tradition and culture of the community, we need to not only preserve but also maintain all of these since it will affect the goal and the establishment of identity of the alley regeneration projects as a significant factor. In addition, in order to attract visitors from diverse cultures, providing cultural or artistic experiences and aesthetic landscapes will be importantly considered as an additional factor for the research. In other words, through this research, I would like to demonstrate that it is the most important for the alleys fell far behind to establish its identity for continuous successful eyre generation projects, which are not temporary.

Depletion of Cytoplasmic Tail of UL18 Enhances and Stabilizes the Surface Expression of UL18

  • Kim, Jung-Sik;Kim, Bon-Gi;Yoon, Il-Hee;Kim, Sang-Joon;Park, Chung-Gyu
    • IMMUNE NETWORK
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    • v.8 no.4
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    • pp.130-136
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    • 2008
  • Background: Human cytomegalovirus UL18, a MHC class I homologue, has been considered a natural killer (NK) cell decoy. It ligates LIR-1/ILT2 (CD85j), an NK inhibitory receptor, to prevent lysis of infected target cells. However, precise role of UL18 to NK cell cytotoxicity is yet elusive. Difficulty in clarifying the function of UL18 lies in complication in detecting UL18 mainly due to low level expression of UL18 on the surface and gradual loss of its expression. Methods: To overcome this hurdle, cDNA of cytoplasmic tail-less UL18 was constructed and expressed in swine endothelial cell (SEC). The expression level and its stability in the cell surface were monitored with FACS analysis. Results: Surface expression of UL18 is up-regulated by removing cytoplasmic tail portion from UL18F (a full sequence of UL18). SECs transfected with a cDNA of UL18CY (a cytoplasmic tail-less UL18) stably expressed UL18 molecule on the surface without gradual loss of its expression during 6 week continuous cultures. In the NK cytotoxicity assay, UL18 functions either inhibiting or activating NK cell cytotoxicity according to the source of NK cells. We found that there is individual susceptibility in determining whether the engagement of NK cell and UL18 results in overall inhibiting or activating NK cell cytotoxicity. Conclusion: In this study, we found that cytoplasmic tail is closely related to the regulatory function for controlling surface expression of UL18. Furthermore, by constructing stable cell line in which UL18 expression is up-regulated and stable, we provided a useful tool to clarify exact functions of UL18 on various immune cells having ILT2 receptor.

Production of Extracellular Polysaccharide by Perfusion Culture of Angelica gigas Nakai Suspension Cells (배지교환식 고농도 배양에 의한 참당귀 현탁세포 유래 ECP 생산)

  • Kim, Young-Hwa;Kim, Ik-Hwan;Kim, Dong-Il
    • KSBB Journal
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    • v.21 no.5
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    • pp.336-340
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    • 2006
  • High-density perfusion cultivation was performed to produce extracellular polysaccharide(ECP) as immunostimulating agents in suspension cell cultures of Angelica gigas Nakai. In batch culture, the maximum cell density was 16.8 gDCW/L at day 6 and 0.9 g/L of ECP was obtained at day 8. When the medium exchange was started at the fifth day after inoculation for the perfusion culture, high concentration of the cells at 23.8 gDCW/L could be achieved with continuous production of ECP. Treatments of ultrasound and Pluronic F-68 were found to be helpful for the secretion of intracellular ECP into the culture medium.

석탄 합성가스로부터 효율적인 생물학적 수소 생산에 관한 연구

  • 강환구;전희진
    • KSBB Journal
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    • v.15 no.3
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    • pp.268-273
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    • 2000
  • A microbiological hydrogen production process was optimized. Anaerobic photosynthetic bacteria like Rhodospirillum rubrum which is known to produce hydrogen from carbon monoxide efficiently and remove sulfur was used. To evaluate the potenital of this microorganism the optimization of media fermentation condition light intensity and light requirement for CO conversionwas tried in batch cultures and the continuous fermenter was also applied for this process. The gas residence time on CO conversion was sought out to get high conversion of carbon monoxide to hydrogen. Through this study the possibility of microbial synthtics gas concersion process was proposed.

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Kinetics of Removing Nitrogenous and Phosphorus Compounds from Swine Waste by Growth of Microalga, Spirulina platensis

  • Kim, Min-Hoe;Chung, Woo-Taek;Lee, Mi-Kyung;Lee, Jun-Yeup;Ohh, Sang-Jip;Lee, Jin-Ha;Park, Don-Hee;Kim, Dong-Jin;Lee, Hyeon-Yong
    • Journal of Microbiology and Biotechnology
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    • v.10 no.4
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    • pp.455-461
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    • 2000
  • Abstract Spirulina platensis was grown in SWlUe waste to reduce inorganic compowlds and simultaneously produce feed resources. Spirulina platensis prefers nitrogenous compounds in Ibe order: $NH_4^{+}-N>NO_3^{-}-N>simple-N$ such as urea and simple amino acids. It even consumes $NH_4^{+}-N$ first when urea or nitrate are present. Therefore, the content of residual $NH_4^{+}-N$ in Spimlina platensis cultures can be determined by the relative extent of the following processes: (i) algal uptake and assimilation; (ii) ammonia stripping; and (iii) decomposition of urea to NH;-N by urease-positive bacteria. The removal rates of total nitrogen ffild total phosphorus were estimated as an indicator of the treatment effIciency. It was found that Spirulina platensis was able to reduce 70-93% of $P_4^{3-}-P$, 67-93% of inorganic nitrogen, 80-90% of COD, and 37-56% of organic nitrogen in various concentrations of swine waste over 12 days of batch cultivation. The removal of inorganic compounds from swine waste was mainly used for cell growth, however, the organic nitrogen removal was not related to cell growlb. A maximum cell density of 1.52 dry-g/l was maintained with a dilution rate of 0.2l/day in continuous cultivation by adding 30% swine waste. The nitrogen and phosphorus removal rates were correlated to the dilution rates. Based on the amino acid profile, the quality of the proteins in the Spirulina platensis grown in the waste was the same as that in a clean culture.ulture.

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Biodegradation of Endosulfan by Klebsiella oxytoca KE-8 Immobilized on Activated Carbon

  • Jo, Min-Sub;Lee, Jung-Bok;Kim, Jang-Eok;Sohn, Ho-Yong;Jeon, Chun-Pyo;Choi, Chung-Sig;Kwon, Gi-Seok
    • Korean Journal of Environmental Agriculture
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    • v.29 no.2
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    • pp.176-183
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    • 2010
  • Endosulfan degrading ability of Klebsiella oxytoca KE-8 immobilized by entrapment with activated carbon was examined. Endosulfan degradation by the immobilized bacterial strains on several different activated carbon based support materials was investigated. Based on results, activated carbon ($8\times30$ mesh) was chosen as a support material. The immobilized Klebsiella oxytoca KE-8 with the cell density of 4 mg $g^{-1}$ (dry weight) degraded 22.18 ug $ml^{-1}$ endosulfan within 5 days at pH 7.0, $30^{\circ}C$ in batch shake flask cultures. Also, we an experimented recycle packed bed column mode and continuous packed bed column mode for endosulfan degradation. Under optimum operation condition, the immobilized cells in a laboratory scale pack bed column with support beads were able to degrade endosulfan completely in defined minimal salt medium at a maximum rate of 129.6 ug $ml^{-1}$ per day. Moreover, the endosulfan degradation activity could be demonstrated at $4^{\circ}C$ for one month without significant decrease in activity. Results of this study suggest that immobilized cells of Klebsiella oxytoca KE-8 might be applicable to endosulfan contaminated site.

Growth and Nutritional Composition of Eustigmatophyceae Monodus subterraneus and Nannochloropsis oceanica in Autotrophic and Mixotrophic Culture

  • Jo, Min Jin;Hur, Sung Bum
    • Ocean and Polar Research
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    • v.37 no.1
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    • pp.61-71
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    • 2015
  • Eicosapentaenoic acid (EPA) produced from marine organisms is widely used in nutraceuticals. Monodus subterraneus and Nannochloropsis oceanica, which are representative freshwater and marine Eustigmatophyceae, respectively, are known to have a high content of protein and lipid, particularly, EPA. In this study, to compare the growth and nutritional composition of M. subterraneus and N. oceanica, they were cultured in autotrophic and mixotrophic conditions with JM and f/2 medium, respectively, at $25^{\circ}C$. In addition, $80{\mu}mol\;photons\;m^{-2}s^{-1}$ with 24-hour and 12-hour light was provided, with the addition of 2% glucose to the medium for the mixotrophic culture. With regard to growth, M. subterraneus showed 10 times higher biomass in a mixotrophic culture than in an autotrophic one. However, no significant difference was observed for N. oceanica between the two culture methods. With respect to nutritional composition, M. subterraneus cultured autotrophically had a higher protein and lipid content, particularly EPA, than that cultured mixotrophically, but no significant difference was found in the two cultures of N. oceanica. Furthermore, M. subterraneus cultured autotrophically with continuous light showed higher nutritional composition, particularly EPA, than N. oceanica. In conclusion, the mass culture of freshwater M. subterraneus is much easier and more economical than marine N. oceanica. In addition, production of EPA will be economically improved if mixotrophic culturing of M. subterraneus is first conducted to maximize the biomass, and then secondary autotrophic culturing is performed.

Effects of Hydrocarbon Additions on Gas-liquid Mass Transfer Coefficients in Biphasic Bioreactors

  • Silva, Teresa Lopes da;Calado, Vitor;Silva, Nadia;Mendes, Rui L.;Alves, Sebastiao S.;Vasconcelos, Jorge M.T.;Reis, Alberto
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.3
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    • pp.245-250
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    • 2006
  • The effects of aliphatic hydrocarbons (n-hexadecane and n-dodecane) on the volumetric oxygen mass transfer coefficient $(k_L\;a)$ were studied in flat alveolar airlift reactor and continuous stirred tank reactors (CSTRs). In the flat alveolar airlift reactor, high aeration rates (>2vvm) were required in order to obtain efficient organic-aqueous phase dispersion and reliable $k_La$ measurements. Addition of 1% (v/v) n-hexadecane or n-dodecane increased the $k_La$ 1.55- and 1.33-fold, respectively, compared to the control (superficial velocity: $25.8{\times}10^{-3}m/s$, sparger orifice diameter: 0.5 mm). Analysis of the gas-liquid interfacial area a and the liquid film mass transfer coefficient $k_L$ suggests that the observed $k_La$ increase was a function of the media's liquid film mass transfer. Addition of 1% (v/v) n-hexadecane or n-dodecane to analogous setups using CSTRs led to a $k_La$ increase by a factor of 1.68 and 1.36, respectively (superficial velocity: $2.1{\times}10^{-3}m/s$, stirring rate: 250 rpm). These results propose that low-concentration addition of oxygen-vectors to aerobic microbial cultures has additional benefit relative to incubation in purely aqueous media.