• Title/Summary/Keyword: Continuous cultures

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Drug Resistance of Mycobacterium Tuberculosis in Korea (한국인 결핵환자로 부터 톨리된 인형결핵균의 약제내성)

  • Kim, Sang-Jae;Hong, Young-Pyo;Han, Yong-Chul;Kim, Sung-Jin
    • Tuberculosis and Respiratory Diseases
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    • v.38 no.2
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    • pp.99-107
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    • 1991
  • Drug resistance of M. tuberculosis has been investigated with isolates from patients screened out of the sample population of the nationwide tuberculosis prevalence surveys or from the routine cultures. The results showed a close inverse relationship between prevalence of drug resistance and efficiency of the past or current treatment regimens of NTP. Individual drug resistance also showed a close relationship with the extent of use of the relevant drugs. Drug resistance was found in 38.0% of M. tuberculosis isolates from patients found in 1965 survey and remained unchanged until it increased upto 48.0% in 1980 survey. The resistance prevalence, however, dropped to 30.8% in 1985 and further to 25.3% in 1990 survey. Such decrease was fairly well coincided with a continuous increase of the treatment efficiency (from 60% in 1984 to 77% in 1989) in 1980s. Initial drug resistance also showed a similar trend, namely 26.2% in 1965, 23.9% in 1970, 20.1% in 1975, 30.6% in 1980, 17.4% in 1985, and 15.0% in 1990. The similar figures were observed in M. tuberculosis isolates from patients diagnosed in the routine services. Higher prevalence of initial drug resistance was observed among urban patients than rural patients and among young patients than old patients. These findings signify that a continuous survey on drug resistance permits to monitor efficiency of treatment programme of the country.

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Batch and Fed-batch Fermentation for the Lovastatin Production by Cerulenin-resistant Aspergillus terreus Mutant (Cerulenin 저항성 Aspergillus terreus 변이주로부터 lovastatin 생산을 위한 회분식과 유가식 배양)

  • 문미경;전계택;정용섭
    • KSBB Journal
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    • v.16 no.1
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    • pp.87-94
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    • 2001
  • The biosynthesis of Lovastatin, a cholesterol lowering agent formed by the filamentous fungus, cerulenin-resistant Aspergillus terreus mutant was studied in shake flasks and bioreactors. The lovastatin production could be improved by fed-batch under the limited condition of carbon source. The relationship between the fungal morphology and the lovastatin production was also examined during the fed-batch cultures. The fed-batch studies in shake flasks were carried out to find the optimum glucose feeding method, and the pulsed feeding of glucose from 3 days onward at 24 hours intervals was found to be optimal to increase the lovastatin production and reduce the average pellet size. When the pH was controlled at around 5.8 during the whole fermentation period, the lovastatin concentration reached 384 mg/L, which is much higher than the values obtained pH-uncontrolled and pH 7.4. The optimal glucose feeding strategies was found that 30 g/L of glucose was added initially in batch mode, and then fed-batch was conducted by continuous addition of glucose solution(180 g/L) from 72 to 240 hr at a rate of 1.2 mL/hr at $28^{\circ}C$, pH 5.8, 400 rpm, and 1.0 vvm. The lovastatin concentration of 547 mg/L was obtained in 168 hr. It was about 1.5 times higher than the value of the batch fermentation.

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Effects of temporary and periodic emersion on the growth of Fucus spiralis and Pelvetia canaliculata germlings

  • Kim, Bo-Yeon;Park, Seo-Kyoung;Norton, Trevor A.;Choi, Han-Gil
    • ALGAE
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    • v.26 no.2
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    • pp.193-200
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    • 2011
  • The stress tolerance ability of Pelvetia canaliculata (L.) Dcne. Et Thur. and Fucus spiralis L. to temporary and periodic emersion stress was examined in order to test the following hypotheses: The upper shore alga, P. canaliculata is more tolerant to desiccation than F. spiralis in the germling stage and the former outgrows the latter under desiccation stress; Germling stress tolerance of the two species is age-specific; Crowding of germlings protects them from desiccation, irrespective of the species involved. Germling growth of the two species was retarded with increasing exposure period and was age-specific, as they were air-exposed at an earlier stage. After 16 days, the length of Pelvetia germlings was similar between 2-day-old germlings (125-140 ${\mu}m$) and 7-day-old germlings (134-140 ${\mu}m$), which were air-exposed during the same period (0, 6, 12, 24, 48, and 72 h) at the two different ages. However, Fucus germlings were significantly larger at 7-day-old germlings (211-277 ${\mu}m$) than at 2-day-old germlings (184-278 ${\mu}m$), especially in the treatments of 48 and 72 h. These results indicate that Fuscus grow faster than Pelvetia and that the growth response of germlings to temporary emersion stress is more sensitive in Fucus than that in Pelvetia. Growth of germlings of both species was reduced with increasing density under favorable growth conditions (submerged control and 6 h / 12 h exposure treatments) in the periodic air-exposed experiments using tidal tanks, but was enhanced under severe emersion stress conditions. P. canaliculata showed better growth at 6 h exposure treatment than that of the control, under continuous submergence, indicating that Pelvetia germlings require a periodic exposure period. Fucus germlings always grew faster than those of Pelvetia and did best in mixed cultures, whereas Pelvetia did least well when mixed with Fucus germlings. The adverse effects of F. spiralis on P. canaliculata were greater than those of Pelvetia cohorts. The outcome of interspecific competition between F. spiralis and P. canaliculata gemlings was slightly altered by exposure period but not to such an extent as to change the outcome.

Dietary value of rotifer fed on the different diets in high density culture for flounder larvae, Paralichthys olivaceus (넙치 자어 사육에 있어서 먹이 종류에 따라 고밀도로 배양한 rotifer의 먹이효율)

  • PARK Huem Gi;LEE Kyun Woo;LEE Sang-Min;KIM Sung Koo;LEE Jong Ha;LIM Young Soo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.33 no.2
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    • pp.93-97
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    • 2000
  • This study was carried out to investigate the effect of rotifer fed the different diets in high density culture on larval flounder Paralichthys olivaceus. Potifer was enriched with enrichment supplements, Marine ${\alpha}\;and\;{\omega}-yeast$ for 6 hours after being cultured with freshwater Chlorella for 18 hours during high density culture before it was fed to larval flounder. And rotifer was culutured with marine Chlorella and freshwater Chlorella for 24 hours during semi-continuous high density culture before it was fed to larval flounder. Culture tanks(21 working volum) set for rotifer culture in a water bath($28{\circ}C$) were continuously supplied with oxygen gas. The content of n-3 HUFA to fatty acids in rotifer(dry weight ${\%}$) enriched with Marine ${\alpha}$ for 6 hours and cultures with marine Chlorella for 24 hours were higher than that in rotifer enriched with ${\omega}-yeast$ for 6 hours or cultured with freshwater Chlorella for 24 hours. The growth and survival rates of larval flounder fed on rotifer enriched with Marine ${\alpha}$ for 6 hours and cultured with marine Chlorella for 24 hours were higher than those of larval flounder fed on rotifer enriched with ${\omega}-yeast$ for 6 hours or cultured with freshwater Chlorella for 24 hours. And the content of n-3 HUFA of larval flounder fed on rotifer enriched with Marine ${\alpha}$ for 6 hours was higher than that of larval flounder fed on other rotifers, The results from this study indicated that rotifer culture with marine Chiorelia would be suitable for the high density culture and effective diet for the growth of larval flounder.

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The Research of User Experiences of Participants of Public Comics Festival - In the center of Cosplay Sector of Bucheon International Comics Festival (공공 만화축제 참여자의 사용자경험에 대한 연구 - 부천국제만화축제의 코스프레 부문을 중심으로)

  • Chang, Jun-Do;Yoon, Wn-Ho
    • Cartoon and Animation Studies
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    • s.42
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    • pp.263-291
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    • 2016
  • Recently, by growing of Korean comics/animation markets and number of consumers, the more people have been reproducing culture contents into derived contents. However, user experience of active users who enjoy these cultures have not been accepted well like other local culture festivals in South Korea, though there are high potentials of vitalization comics/animation festivals using the active users. In this study, the experiences of participants of BICOF (Bucheon International Comics Festival) from 2013 to 2014 researched using the method of ethnography, especially using (group) interviews and participant observations. The result from the research indicates that cosplayers have limited range of participation inside of festival. And they have negative experiences during their participation into festivals. Therefore, this study suggests necessity of methodology of continuous reflecting of the user experiences of active users into festival, for the solution of the successful festival, who was objectified in the festival.

Contents Development Related to Costume Culture in Traditional Intangible Cultural Properties -The Modernization of Costume Design in Dongraeyaryu- (전통무형문화재의 복식문화컨텐츠 개발 -동래야류 의상 디자인의 현대화 작업)

  • Kim, Soon-Ku
    • Archives of design research
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    • v.17 no.4
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    • pp.251-258
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    • 2004
  • Today we seem to be flooded with digital culture as the age of information has reached its peak. As fusion culture has been generalized, in which the arts and culture of the East and the West are in harmony, and quality of life has been improved, people are enjoying more abundant cultural benefits than ever. In such a situation, we may lose the origin of our culture and disregard our traditional culture due to the mixture of cultures. In addition, it is necessary at this point to distinguish pure culture from mixed one and to re-illuminate the value of our original culture for the next generation. Therefore, the author took interested in Dongraeyaryu, a large-scale festival in Busan, which has been designated as an important intangible cultural property, and carried out a research for its continuous instruction and activation. among contents such as music, costume, dancing and stage properties that compose intangible cultural property, this study selected costume, which has significant visual effects and large differences in shape between old one and contemporary one, for development. By proposing modernized design of costume preferred by the new generation and in harmony with the masks, this study wished to narrow the generation gap, to direct young people's attention to the learning of tradition and to propose motives that activate the culture of local festival.

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Labor market forecasts for Information and communication construction business (정보통신공사업 인력수급차 분석 및 전망)

  • Kwak, Jeong Ho;Kwun, Tae Hee;Oh, Dong-Suk;Kim, Jung-Woo
    • Journal of Internet Computing and Services
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    • v.16 no.2
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    • pp.99-107
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    • 2015
  • In this era of smart convergent environment wherein all industries are converged on ICT infrastructure and industries and cultures come together, the information and communication construction business is becoming more important. For the information and communication construction business to continue growing, it is very important to ensure that technical manpower is stably supplied. To date, however, there has been no theoretically methodical analysis of manpower supply and demand in the information and communications construction business. The need for the analysis of manpower supply and demand has become even more important after the government announced the road map for the development of construction business in December 2014 to seek measures to strengthen the human resources capacity based on the mid- to long-term manpower supply and demand analysis. As such, this study developed the manpower supply and demand forecast model for the information and communications construction business and presented the result of manpower supply and demand analysis. The analysis suggested that an overdemand situation would arise since the number of graduates of technical colleges decreased beginning 2007 because of fewer students entering technical colleges and due to the restructuring and reform of departments. In conclusion, it cited the need for the reeducation of existing manpower, continuous upgrading of professional development in the information and communications construction business, and provision of various policy incentives.

Isolation of Microorganisms for Petroleum Desulfurization and Evaluation of Its Desulfurization Activity for Diesel Oil (석유 탈황용 미생물 분리 및 디젤유에 대한 탈황능 평가)

  • Sohn, Ho-Yong;Chang, Je Hwan;Chang, Yong Keun;Chang, Ho Nam;Ryu, Hee Wook;Cho, Keoung Sook
    • Clean Technology
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    • v.2 no.1
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    • pp.53-59
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    • 1996
  • For the development of biocatalysts and processes for microbial desulfurization of petroleum, more than 60 microbial strains capable of DBT(Dibenzothiophene) degradation were isolated from oil-polluted soils through 3 months of continuous and enrichment cultures. Among them, A23-3 strain could grow on DBT as the only sulfur source, while hexadecane was not utilized as a carbon source. The rate of desulfurization by A23-3 in a DBT-glucose medium was satisfactory. The addition of yeast extract or trace metal solution accelerated the rate of desulfurization about 4.5~6.5 times. In case of actual diesel oil treatment, the specific rate of DBT degradation was $0.045g-DBT\;per\;g-cell{\cdot}hour$. A number of aromatic compounds heavier than $C_{14}$ in diesel oil were also degraded by A23-3. A23-3 strain was evaluated as a good catalyst for the production of low-sulfur, low-aromatic clean diesel oil.

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Isolation and Culture of In Vitro Cultured Populus alba×P. grandidentata Protoplasts (Populus alba×P. grandidentata 조직배양(組織培養) 식물체(植物體) 원형질의 분리(分離)와 배양(培養))

  • Chun, Young Woo
    • Journal of Korean Society of Forest Science
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    • v.71 no.1
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    • pp.45-49
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    • 1985
  • Protoplast-source meterial and enzyme strength had a significant influence on protoplast yield from hybrid poplar, Populus alba ${\times}$ P. grandidentata. The yield of protoplasts from in vitro culture of 1 month-old plantlets was more than that from greenhouse grown 4 month-old stock plant. In vitro cultured plantlets regulary produced more viable protoplasts with E-I enzyme solution (0.5% cellulase and 0.1% macerase) than those with E-II enzyme solution (1.0% cellulase and 0.2% macerase) after overnight incubation. The mean yield of protoplasts from in vitro cultured plantlets was $4{\times}10^6$ with E-I enzyme solution. Cell division was observed in these protoplast cultures after 7-10 days. Protoplast-derived hybrid poplar cells survived over 3 weeks in culture and some continuous cell divisions were evident. Other aspects associated with protoplasts from in vitro cultured plantlet are also discussed.

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Production of Ginsenoside in Callus of Ginseng Hairy Roots (인삼 모상근의 캘러스를 이용한 ginsenoside 생산)

  • Kwon, Jung-Hee;Cheon, Hyun-Choon;Yang, Deok-Cho
    • Journal of Ginseng Research
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    • v.27 no.2
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    • pp.78-85
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    • 2003
  • By the Agrobacterium rhizogenes A$_4$ were induced a transformed callus of ginseng hairy root and examine to find the possibility whether it can produce certain ginsenoside. Investigations for a finding out to optimal culture medium showed that BA application is better than more factorial composition between auxins and cytokinins. For the induction of hairy root callus of ginseng, l/2 MS medium containing 1 to 3 mg of benzyladenine(BA) per liter gave the best result. The growth of ginseng hairy root callus(GHC) cultured with the 1/2MS medium supplemented with 2 mg BA/L was selected for best suspension cultures. The optimum concentration of BA for ginsenosides production was found to be 2 mg/L. Probably the inoculum size of callus plays a role with the ginsenoside production in suspension culture. AS for inoculum size of callus, 50 mg was superior to 150 mg for growth and ginsenoside production. Ginsenoside contents were highest in the suspension culture grown for four weeks under continuous light condition. In fact that continous light treatment promote strongly the synthesis of ginsenoside of the hairy root callus is first result in the world and the numerously induced root hairs of the callus leads a new method for ginsenoside production.