• Title/Summary/Keyword: Continuous Culture

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Effects of p variation and phosphate limitation on the continuous fermentation of Clostridium acetobutylicum (pH 변화와 인산 제한이 Closoidium acetobutylicum의 연속발효에 미치는 영향)

  • 신순영;김병흥
    • KSBB Journal
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    • v.5 no.1
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    • pp.9-17
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    • 1990
  • The growth and fermentation profiles of Clostridium acetobutylicum KCTC 1037 were examined in batch and continuous modes with pH variation and phosphate limitation. Clostridium acetobutylicum KCTC 10 37 grew better at pH 4.5 than at pH 5.5 or 6.5. Acetate and butyrate were produced at pH 5.5, whereas culture at pH 4.5 produced acetone and butanol. Solvent production was increased by the phosphate limitation in a batch culture, but in a phosphate-limited continuous culture for 400 hours steady-state solventogenesis was not observed. The induction and maintenance of solventogenesis presumably require not only acidic condition or phosphate limitation but also favourable bioenergetic condition.

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Plant Regeneration from Rice Microspore Cultures (벼의 소포자 배양을 통한 식물체 재분화)

  • 김영수
    • Journal of Plant Biology
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    • v.36 no.2
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    • pp.183-192
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    • 1993
  • Efficient plant regeneration system was established through the culture of rice (Oryza sativa L.) microspores. Microspores released by anther shedding culture developed into proembryos and calluses in B5 medium within two weeks of culture. The optimal hormone and carbon sources were dependent on the genotypes used. Microspore's viability decreased rapidly in culture time, therefore less than 3% of the total microspores were viable at the 9th day when the first microspore division was observed. Of two types of microspores (pollen dimorphism) observed in culture, only the P-grain, larger microspores than normal one was able to divide. Using 4',6-diamidino-2-phenylindole (DAPI) fluorescence staining, it was confirmed that the symmetrical division of uninucleate microspore was the first step leading to continuous microspore development. Microspore-derived proembryos and calluses were regenerated to plants in N6 medium containing 1 mg/L NAA and 5 mg/L kinetin, and 78.3% of the regenerated plants were haploids.

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Process Kinetics of Nisin Production in Batch and Continuous Culture (회분식 및 연속식 배양시 Nisin의 생산특성)

  • Yoo, Jin-Young;Park, Shin-Yang;Jin, Young-Ok;Koo, Young-Jo;Chung, Kun-Sub
    • Microbiology and Biotechnology Letters
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    • v.17 no.5
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    • pp.504-509
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    • 1989
  • Fermentation condition of Streptococcus lactis IFO 12007 for nisin production was examined. The optimal glucose concentration was 60g/ι. The pH and temperature optimum were 6.5 and 31$^{\circ}C$, respectively. The maximum nisin activity in batch culture was 2000IU/$m\ell$. The fermentation quotients after 7 hours of fermentation in batch culture were; specific glucose uptake rate:0.59g/g/h , specific nisin productivity: 34924IU/g/h, product yield: 5944IU/g, growth yield:0.24, biomass:4.81g/ι. The specific growth rate was affected by pH and temperature and the activation energy for growth was 1.35kcal/mole. pH control was essential for nisin production. Fed-batch culture using 20g/$\ell$ glucose medium produced 1420IU/$m\ell$ after 14 hours. The continuous culture could be operated at below 0.38h$^{-1}$ for nisin production. The steady state nisin concentration and specific nisin productivity were 740IU/$m\ell$ and 45000IU/g/h. The growth yield and maintenance energy were 0.144 and 207mg glucose/g-cell/h.

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Effect of Light on Production of Athocyanin and Betacyanin Thruough Cell Suspension Culture Systems in Vitis vinyfera L. and Phytolacca americana L. (포도와 미국자리공 세포현탁배양계 안토시아닌과 베타시아닌에 미치는 광의 영향)

  • 최관삼;인준교;이영복
    • Korean Journal of Plant Tissue Culture
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    • v.21 no.1
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    • pp.47-53
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    • 1994
  • The effects of light on the production of anthocyanin and betacyanin in cell suspension cultures of Vitis vinifera and Phytolacca americana were investigated. The cell growth of V.vinifera was little affected by exposure to light, but that of P.americana was markedly increased by light than in the dark In suspension cultures of V vinifera maximum accumulation of anthocyanin was observed during the stationary phase in continuous light By contrast, in suspension cultures of R americana, accumulation of betacyanin occured in parallel with cell division which showed two peaks after 4 days and 8 days of culture in continuous light whereas in continuous dark accumulation of anthocyanin and betacyanin did not occured However treatment of light interrupting for l, 12, and 24 h after 4 days in cell suspension. cultures of remarkably showed a slight anthocyanin accumulation, but after 8 days of culture remarkably accumulated by light interrupting for more than 12 h. In cultures of P. americana, the light treatment was more effective at 4th day than at 7th day after culture, but betacyanin accumulation was decreased again in the dark after light treatment These result indicate that the difference of light responses exist between the V.vinifera and the betacyanin of P. americana though cell suspension culture systems.

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Monitoring Anaerobic Reductive Dechlorination of TCE by Biofilm-Type Culture in Continuous-Flow System (연속흐름반응조에서 바이오필름형태의 탈염소화 미생물에 의한 TCE분해 모니터링)

  • Park, Sunhwa;Han, Kyungjin;Hong, Uijeon;Ahn, Hongil;Kim, Namhee;Kim, Hyunkoo;Kim, Taeseung;Kim, Young
    • Journal of Soil and Groundwater Environment
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    • v.17 no.5
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    • pp.49-55
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    • 2012
  • A 1.28 L-batch reactor and continuous-flow stirred tank reactor (CFSTR) fed with formate and trichloroethene (TCE) were operated for 120 days and 56 days, respectively, to study the effect of formate as electron donor on anaerobic reductive dechlorination (ARD) of TCE to cis-1,2-dichloroethylene (c-DCE), vinyl chloride (VC), and ethylene (ETH). In batch reactor, injected 60 ${\mu}mol$ TCE was completely degraded in the presence of 20% hydrogen gas ($H_2$) in less than 8 days by anaerobic dechlorination mixed-culture (300 mg-soluble protein), Evanite Culture with ability to completely degrade tetrachloroethene (PCE) and -TCE to ETH under anaerobic conditions. Once the formate was used as electron donor instead of hydrogen gas in batch or chemostat system, the TCE-dechlorination rate decreased and acetate production rate increased. It indicates that the concentration of hydrogen produced in both systems is possibly more close to threshold for homoacetogenesis process. Soluble protein concentration of Evanite culture during the batch test increased from 300 mg to 688 mg for 120 days. Through the protein monitoring, we confirmed an increase of microbial population during the reactor operation. In CFSTR test, TCE was fed continuously at 9.9 ppm (75.38 ${\mu}mol/L$) and the influent formate feed concentration increased stepwise from 1.3 mmol/L to 14.3 mmol/L. Injected TCE was accumulated at 18 days of HRT, but TCE was completely degraded at 36 days of HRT without accumulation of the injected-TCE during the left of experiment period, getting $H_2$ from fermentative hydrogen production of injected formate. Although c-DCE was also accumulated for 23 days after beginning of CFSTR operation, it reached steady-state in the presence of excessive formate. We also evaluated microbial dynamic of the culture at different chemical state in the reactor by DGGE (denaturing gradient gel electrophoresis).

Effects of Sperm Pretreatments and In vitro Culture Systems on Development of In vitro Fertilized Embryos Derived from Prepubertal Boer Goat Oocytes in China

  • Lv, Lihua;Yue, Wenbin;Liu, Wenzhong;Ren, Youshe;Li, Fuzhong;Lee, Kyung-Bon;Smith, George W.
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.7
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    • pp.969-976
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    • 2009
  • Use of oocytes from prepubertal animals for in vitro embryo production holds potential application for reducing generation intervals and increasing genetic progress through embryo transfer. The objective of these studies was to compare the effect of three sperm pretreatments (prior to in vitro fertilization) and seven embryo culture protocols on fertilization rate and (or) subsequent development of in vitro fertilized embryos derived from oocytes harvested from ovaries of 1-6 month old prepubertal Boer goats in China. Cleavage rates were highest for embryos fertilized with heparin-treated versus calcium ionophore- or caffeine-treated sperm. Similar rates of blastocyst development were observed using heparin- and ionophore-treated sperm, which were higher than obtained with caffeine-treated sperm. No differences in cleavage or blastocyst rates were observed following embryo culture in basal medias (synthetic oviductal fluid (SOF), Charles Rosenkrans 1 (CR1) or tissue culture medium-199 (TCM-199)) containing 10% fetal bovine serum (FBS). Cumulus or oviductal cell co-culture did not enhance cleavage or blastocyst rates relative to culture in SOF+10% FBS. Replacement of FBS in SOF medium with 0.3% BSA increased cleavage rates, but did not increase rates of blastocyst development. Sequential culture in SOF+0.3% BSA followed by SOF+10% FBS increased blastocyst yield versus continuous culture in SOF+10% FBS and tended to increase blastocyst yield versus continuous culture in SOF+0.3% BSA. These results demonstrate a pronounced effects of sperm pretreatments and in vitro embryo culture systems on rates of blastocyst development and provide a potential protocol (sperm pretreatment with heparin and sequential embryo culture in SOF+0.3% BSA followed by SOF+10% FBS) for generation of the significant numbers of in vitro produced blastocysts from oocytes of prepubertal Boer goats necessary for application of embryo transfer in rural regions of China for distribution of Boer goat genetics.

Identification of Factors Regulating Escherichia coli 2,3-Butanediol Production by Continuous Culture and Metabolic Flux Analysis

  • Lu, Mingshou;Lee, Soo-Jin;Kim, Bo-Rim;Park, Chang-Hun;Oh, Min-Kyu;Park, Kyung-Moon;Lee, Sang-Yup;Lee, Jin-Won
    • Journal of Microbiology and Biotechnology
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    • v.22 no.5
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    • pp.659-667
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    • 2012
  • 2,3-Butanediol (2,3-BDO) is an organic compound with a wide range of industrial applications. Although Escherichia coli is often used for the production of organic compounds, the wild-type E. coli does not contain two essential genes in the 2,3-BDO biosynthesis pathway, and cannot ferment 2,3-BDO. Therefore, a 2,3-BDO biosynthesis mutant strain of Escherichia coli was constructed and cultured. To determine the optimum culture factors for 2,3-BDO production, experiments were conducted under different culture environments ranging from strongly acidic to neutral pH. The extracellular metabolite profiles were obtained using high-performance liquid chromatography (HPLC), and the intracellular metabolite profiles were analyzed by ultra-performance liquid chromatography and quadruple time-of-flight mass spectrometry (UPLC/Q-TOF-MS). Metabolic flux analysis (MFA) was used to integrate these profiles. The metabolite profiles showed that 2,3-BDO production favors an acidic environment (pH 5), whereas cell mass favors a neutral environment. Furthermore, when the pH of the culture fell below 5, both the cell growth and 2,3-BDO production were inhibited.

Development of Continuous Culture Process for Economic Production of Hyaluronic Acid (HA) Biosynthesized by Streptococcus zooepidemicus (Streptococcus zooepidemicus 유래 히알루론산의 경제적 생산을 위한 연속배양 공정 개발)

  • Kim, Soo Yeon;Chun, Gie-Taek
    • Microbiology and Biotechnology Letters
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    • v.48 no.4
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    • pp.525-532
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    • 2020
  • A continuous fermentation process was carried out to enhance hyaluronic acid (HA) production using Streptococcus zooepidemicus cells. During the 1st stage continuous operation from 8 h with a dilution rate of 0.029/h (D1), HA was produced in the range of 7.5-10 g/l. During the 2nd stage from 44 h with a dilution rate of 0.036/h (D2), HA production (8.28 g/l) was initially reduced to a small extent due to increase of dilution rate from D1 to D2, and then a new pseudo-steady state was formed within a few hours with a concurrent small variations of HA production. The HA amount produced during the latter part of the 2nd stage was stably maintained in the range of 8.28-9.48 g/l, about 4.7% less amount compared to the 1st stage. Due to 24% increase of dilution rate from D1 to D2, however, maximum volumetric productivity (DP) amounting to 0.341 g/l/h was obtained at 96 h during the 2nd stage. This maximum productivity obtained from the continuous culture turned out only a small increase (3%) as compared to the corresponding batch fermentation. However, it should be noted that, in the case of batch process, one run typically consists of serial stages of growth culture plus one final production culture. This implies that, if the continuous fermentation that practically needs no dead time necessary for the multi-stage growth cultures is run for longer period, the total amount of the accumulated HA would be far greater than the amount obtained from the corresponding batch culture performed for the identical period.

Research of the Safety Culture Level in Korea Railway Corporations (국내 철도운영기관 철도안전문화수준 조사)

  • Son, Myung Sun;Lee, Hi Sung;Choi, Yang Gyu
    • Journal of the Korea Safety Management & Science
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    • v.17 no.2
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    • pp.79-88
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    • 2015
  • The safety culture of an organization is the product of individual and group values, attitudes, perceptions, competencies, and patterns of behavior that determine the commitment, the style and proficiency, and an organization's health and safety management. A good safety culture includes effective, appropriate safety management systems; strong safety leadership & commitment from management; participation and involvement of the workforce; and organizational learning and continuous improvement. This paper will introduce the safety culture inspection standards and process in Korea Railway. The main purpose is to get a better understanding of safety culture and to develop measuring tool. First of all we developed the composition factor of safety culture and the question set. And we prepared the base of computerization of safety culture measurement by developing of evaluation standards and weighted value.

Productivity of freshwater Rotifer, Brachionus calyciflorus and Marine Rotifer, B. rotundiformis in the Semi-continuous High Density Culture (Rotifer 반 연속 고밀도. 배양에 있어서 담수산 rotifer, Brachionus calyciflorus와 해수산 rotifer, B. rotundiformis의 생산성)

  • LEE Kyun Woo;PARK Heum Gi;CHO Sung Hwaon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.34 no.2
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    • pp.156-159
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    • 2001
  • The experiment was carried out to investigate the productivity of freshwater rotifer, Brachionus calyciflorus and marine rotifer, B. rotundiformis at various temperatures, initial inoculation and pH in a 5 L semi-continuous high density culture. Rotifers were fed by commercial condensed freshwater Chlorella. When pH was not controlled, average daily productions of freshwater and marine rotifers increased with temperature. The highest production, $44\times10^6$ rotifers, was achieved of B. calyciflorus at $32^{\circ}C$ and the possible production lasting period of B. calyciflorus was shorter than that of B. rotundiformis. Under the adjustment of pH at 7, the possible production lasting periods of B. calyciflorus and B. rotundiformis inoculated with 5,000 inds./mL were longer than those of rotifers inoculated with 10,000 inds./mL, and the daily production rate of the former was higher than that of the latter. The results from this study indicated that optimum density of the initial inoculation for the cultivation of B. calyciflorus and B. rotundiformis was 5,000 inds,/mL under the controlled conditions of pH 7 and at $32^{\circ}C$ in a semi-continuous high density culture, in terms of production rate and food cost aspects.

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