• 제목/요약/키워드: continuous cultures

검색결과 143건 처리시간 0.029초

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

  • 김기청
    • 한국응용곤충학회지
    • /
    • 제15권3호
    • /
    • pp.153-159
    • /
    • 1976
  • Sclerotinia sclerotiorum(Lib.) de Bary의 상치, 오이 및 유채의 3균주에 대하여 PDA를 기본부지로하여 광선이 이들의 균핵형성에 미치는 영향을 연구하였다. 광원으로서는 주광색 형광등을 사용하였다. 그 결과를 요약하면 다음과 같다. 1) 계속광처리에서 광도 480Lux까지는 광도가 증가함에 따라 증가했지만 성숙균핵의 건물중은 이와는 반대로 감소하였다. 그리고 800 Lux 처리에서는 균핵시원체의 유기가 크게 억제되었고 성숙균핵은 거의 형성되지 않았다. 2) 5000Lux의 고광도라 하더라도 48시의 단시간처리는 균핵시원체수 및 성숙균핵수를 증가시켰다. 그러나 성숙균핵의 건물중은 160 Lux에서만 다소 증가하는 경향이 있었다. 3) 광 shock 즉 1분간치의 계속광 48시간까지의 160 Lux, 500Lux 처리는 모두 균핵형성수와 건물중을 증가시켰는데 균핵형성수와 건물중을 증가시켰는데 균핵형성수는 500Lux에서 균핵건물중은 160Lux에서 더 높았다.

  • PDF

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

  • 박민선;장종화
    • 한국치위생학회지
    • /
    • 제18권3호
    • /
    • pp.385-397
    • /
    • 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.

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

  • 박건우
    • 한국실내디자인학회논문집
    • /
    • 제26권3호
    • /
    • pp.3-12
    • /
    • 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
    • /
    • 제8권4호
    • /
    • pp.130-136
    • /
    • 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.

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

  • 김영화;김익환;김동일
    • KSBB Journal
    • /
    • 제21권5호
    • /
    • pp.336-340
    • /
    • 2006
  • 본 연구에서는 참당귀 현탁세포배양에 의한 면역 증강성 ECP의 생산을 증진시키기 위하여 배지교환식 배양을 수행하였으며, ECP의 분비를 촉진하는 초음파 처리와 Pluronic F-68의 영향을 조사하였다. 참당귀의 현탁세포배양시, 최대 세포생장은 6일째에 16.8 g DCW/L였고, ECP의 생산은 세포생장과 함께 증가하다가 8일째에 최고 0.9 g/L가 생산되었다. 식물세포 고농도배양법인 배지교환식 배양을 적용해, 초기 당 농토를 높이고 접종 후 5일부터 연속적으로 배지교환을 해주어 23.8 gDCW/L의 고농도의 현탁세포를 얻을 수 있었다. 초음파 처리 및 Pluronic F-68의 첨가는 참당귀 세포의 세포막의 투과성을 증진시켜 ECP의 생산성을 높임과 동시에 세포 내의 다당의 배지로의 배출을 유도한 것으로 판단된다.

석탄 합성가스로부터 효율적인 생물학적 수소 생산에 관한 연구

  • 강환구;전희진
    • KSBB Journal
    • /
    • 제15권3호
    • /
    • pp.268-273
    • /
    • 2000
  • 본 연구에서는 R rubrum을 이용한 석탄합성 가스로부터 수소 생산공정에 있어서의 세포성장 및 일산화탄소 전환을 최적화하 는 여러 조건들을 조사하였다. 그 중 pH의 영향을 살펴보면 R. rubrum 세포성장에는 pH 6~7이 최적이었고 수소생산에는 pH 7 7-7.5이 최적이었으며 pH가 5.5에서는 세포성장이거의 이루어 지지 않았다. 또한 온도가 34 'C 이상 증가되었을 때 세포성장이 둔화되어 멈추고 안정적인 co 전환속도를 얻을 수 없으므로 $30^{\circ}C$가 R. rubrum 균주 성장과 co 전환에 최적온도라 생각된다. 또한 R. rubrum은 photosynthetic bacteria인데 이 세포의 성장에 는 벚의 세기가 1,700-2,400 Lux가 최적임을 알 수 있었고 co 전환에는 계속적인 빛의 공급이 꼭 필요하지는 않고 간헐적인 빛의 노출만으로도 충분하다고 생각된다. 또한 연속반응기를 이 용하여 600 rpm, $30^{\circ}C$, pH 7에서 합성가스 체류시간 110분시 co 전환율 약 53%정도를 얻을 수 있었다. 이 연구가 계속 진 행되어져서 photobioreactor의 개발, high pressure bioreactor의 이 용, 균주의 mutatIOn 및 전환능력 우수 균주 등의 selection을 수 행한다면 매우 높은 합성가스 전환율을 갖는 생물반응기 공정개 발도 가능하리라 생각된다.

  • PDF

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
    • /
    • 제10권4호
    • /
    • pp.455-461
    • /
    • 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.

  • PDF

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
    • 한국환경농학회지
    • /
    • 제29권2호
    • /
    • pp.176-183
    • /
    • 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
    • /
    • 제37권1호
    • /
    • pp.61-71
    • /
    • 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
    • /
    • 제11권3호
    • /
    • pp.245-250
    • /
    • 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.