• Plant Biotechnology Reports
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• 제5권2호
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• pp.121-126
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• 2011

Isoflavonoid production in cell cultures of Pueraria tuberosa as influenced by an angiospermic parasite, Cuscuta reflexa, was studied. During the time course, maximum isoflavonoid content was recorded when Cuscuta elicitor was added on day 15 of culture. Among various concentrations of elicitor tried, $1g\;l^{-1}$ of Cuscuta elicitor was found to be the most effective. The optimized elicitation conditions were used in vessels of varying capacity where maximum yield of ${\sim}91mg\;l^{-1}$ of isoflavonoid was recorded in a 2-l bioreactor which was about 19% higher than the control cultures. In this case, puerarin content increased up to $11mg\;l^{-1}$ which was 580% higher that the value recorded in the control cultures. In the bioreactor, 8 days of elicitation was optimal for the high accumulation of isoflavonoid, giving productivity of ${\sim}4mg\;l^{-1}\;day^{-1}$. The study showed persistent high isoflavonoid yield even during scale-up. Use of a preparation of Cuscuta reflexa as an elicitor is reported for the first time. The increase in isoflavonoid content was elicitor dose-dependent and can be explored to trigger high yields of isoflavonoid/secondary metabolites in production.

• Journal of Microbiology and Biotechnology
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• 제25권5호
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• pp.559-568
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• 2015

Kimchi is a traditional Korean vegetable product that is naturally fermented by various microorganisms present in the raw materials. Among these microorganisms, lactic acid bacteria dominate the fermentation process. Natural fermentation with unsterilized raw materials leads to the growth of various lactic acid bacteria, resulting in variations in the taste and quality of kimchi, which may make it difficult to produce industrial-scale kimchi with consistent quality. The use of starter cultures has been considered as an alternative for the industrial production of standardized kimchi, and recent trends suggest that the demand for starter cultures is on the rise. However, several factors should be carefully considered for the successful application of starter cultures for kimchi fermentation. In this review, we summarize recent studies on kimchi starter cultures, describe practical problems in the application of industrial-scale kimchi production, and discuss the directions for further studies.

• 대한지역사회영양학회:학술대회논문집
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• 대한지역사회영양학회 2005년도 10th Anniversary International Symposium
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• pp.33-38
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• 2005

During the 20th century, humankind went through the most significant changes in history, from industrial and agricultural revolutions to the invention of the personal computers and the internet, and changes continue to come at an even faster rate. One of notable change is emerging multicultural societies. People tended to live in a monocultural society and new cultures were infused in controlled and confined manners, however, people now live and eat in a continuously changing multicultural society Multicultural societies are emerged from the translocation of people (immigration) and, in a larger sense, globalization. Immigrants are faced with various and different cultures from their own, resulting in excitements and agonies in finding balance among many cultures. People who have not translocated themselves must also deal with various imported foreign cultures from fastfood restaurants to food beliefs. This lecture will use Korean Americans as an example to discuss how immigrants navigate different cultures and environments and how acculturation, the process of adaptation, affects their diet and health. In addition, how globalization has changed people's eatery will be briefly discussed. Understanding impacts of living and eating in a multicultural society is meaningful and useful to find effective approaches to promote healthy lifestyles to people in this fast changing times.

• Journal of Microbiology and Biotechnology
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• 제8권6호
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• pp.631-638
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• 1998

Studies were made to elucidate the cell growth and the production of camptothecin and its derivatives in cell cultures of Camptotheca acuminata. High resolution HPLC chromatograms to analyze camptothecin and 10-hydroxycamptothecin in lactone and carboxylate forms were obtained with a fluorescence detector. Calli inductions were optimized with the young stem of explant on Schenk and Hildebrandt (SH) medium supplemented with 5 mg/l $\alpha$-naphthaleneacetic acid (NAA), 0.2 mg/l 6-benzylamino purine (BAP), 2.0% sucrose, and 0.5% agar. The hybrid medium, a mixture of SH and Murashige and Skoog (MS) salts, was developed for homogeneous suspension cultures without large cell aggregates. The optimum phytohormone concentrations for successful suspension cultures were 1.0mg/l of 2,4-D and 0.5 mg/l of kinetin. The highest growth in suspension cultures was observed when 49.7% (w/w) of the cells was composed of small aggregates which were below 0.1 mm in diameter. Time course changes of cell growth and camptothecin production showed that camptothecin accumulation was started at the end of the growth phase and the maximum content was obtained 10 days after inoculation. Yeast extract elicitor increased camptothecin accumulation 4 times. Methyl jasmonate and jasmonic acid also increased camptothecin production 6 and 11 times, respectively.

• Journal of Plant Biotechnology
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• 제3권2호
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• pp.83-88
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• 2001

A cell culture system of poplar (Populus alba x P.glandulosa) was established to test four different methods for evaluation of cellular stresses. Two different kinds of stresses were given to the cultures by adding either Pb(NO$_3$)$_2$ or paraquat and the cellular responses were monitored during a week period. While fresh weight reduction was observable in two days after the treatment of Pb(NO$_3$)$_2$, such changes were apparent only in later stage in paraquat treated cultures. Cells in paraquat treated cultures in the first 3 days showed no alteration in fresh weight as compared to untreated cultures, but had their MTT reducing activities completely inhibited. Neither Evans blue staining nor ion conductivity of the medium was consistent with fresh weight changes of the cultures. Overall, cell clumps formed during suspension culture appeared to interfere with staining and washing reactions and thus cause the assays unreliable. Among the four methods examined, fresh weight changes and MTT reducing activity appeared to be the most reliable and consistent.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.88-94
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• 2005

Plant tissue culture studies have been done for the preservation of medicinal plant resources and efficient production of pharmaceutically important secondary metabolites. Micropropagation methods for Cephaelis ipecacuanha have been established and these methods enabled much more efficient propagation of the plants than the conventional methods using seedling or layering. The C. ipecacuanha plants derived from tissue culture grew uniformly in the field and they showed higher alkaloid contents compared to the plants grown from seedlings. Hairy root cultures of C. ipecacuanha and Panax ginseng have been established by infection with Agrobacterium rhizogenes, and the production of important pharmaceuticals by these cultures have been successfully demonstrated. In the case of C. ipecacuanha, the highest alkaloid yields from the hairy roots cultured for 8 weeks were 2.75-fold cephaeline (5.5 mg) and one third emetine (0.7 mg) compared with those from the roots of one-year old plant propagated through shoot-tip culture and cultivated in a greenhouse (2.0 mg cephaeline and 2.0 mg emetine). In the case of P. ginseng, ginsenoside contents in the hairy roots optimally cultured for 4 weeks were much higher than those in the roots of 4-year old field-grown plant. Thus our medicinal plant tissue cultures demonstrate desirable properties. However, they are always exposed to danger of microbial contamination or unexpected trouble of culture facilities. Cryopreservation of plant tissue cultures is a reliable method for long-term preservation. Cryopreservation studies on these cultures are also presented.

• 한국식품위생안전성학회지
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• 제4권2호
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• pp.155-163
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• 1989

YS-medium(0.1% Yeast extract +10% Skimmilk)중에 유산간균 L.casei, L. acidophilus , L. bulgaricus 와 병원성 E, coli, Sal. enteritides를 혐기적으로 혼합배양하면서 각각의 생육과 저해를 조사한 결과 , E. coli와 Sal. enteritideis의 생육이 각 유산균에 의하여 현저하게 저해되었다. 그러나 L.casei와 L.acidophilus의 각 유산균은 E.coli와 Sal. enteritidis에 의하여 생육이 전혀 저해되지 않았고 , L. bulgaricus는 E. coli 에 의하여 약간 저해를 받았다. E. coli와 Sal. enteritidis 의 단독배양액의 pH는 72시간째에 각각 5.08과 5.70이었으며, 유산균혼합배양액의 pH는 3.75~4.48이었고, 병원성균의 생육억제작용은 주고 pH 저하에 기인하였다.

• International Journal of Oral Biology
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• 제34권3호
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• pp.143-150
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• 2009

Amino acid transporters play important roles in supplying nutrients to cells. In our current study, we investigated the expression of LAT1 and measured the amino acid uptake in ameloblast cultures to further elucidate the roles of this transporter during the differentiation of these cells. RT-PCR, observations of cell morphology, Alizaline red-S staining, and uptake analyses were performed following the experimental induction of differentiation in the cultures. LAT1 mRNA was detectable and found to gradually increase over time whereas LAT2 mRNA was not evident in the ameloblast cultures. Transcripts of 4F2hc, a cofactor of LAT1 and LAT2, were also found to be expressed in ameloblast cultures and increase with time. Amelogenin mRNA was expressed in the early stage ameloblast cultures. L-leucine uptake was observed to increase over 14 days of growth in culture. Our data suggest that LAT1 has a key role in the differentiation of ameloblasts and in providing these cells with neutral amino acids, including several essential amino acids.

• Journal of Plant Biotechnology
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• 제36권4호
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• pp.309-319
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• 2009

Transgenic plant cell cultures for the production of biopharmaceuticals including monoclonal antibodies, recombinant proteins have been regarded as an alternative platform in addition to traditional microbial fermentation and mammalian cell cultures. Plant-made pharmaceuticals (PMPs) have several advantages such as safety, cost-effectiveness, scalability and possibility of complex post-translational modifications. Increasing demand for the quantity and diversity of pharmaceutical proteins may accelerate the industrialization of PMP technology. Up to date, there is no plant-made recombinant protein approved by USFDA (Food and Drug Administration) for human therapeutic uses due to the technological bottlenecks of low expression level and slight differences in glycosylation. Regarding expression levels, it is possible to improve the productivity by using stronger promoter and optimizing culture processes. In terms of glycosylation, humanization has been attempted in many ways to reduce immune responses and to enhance the efficacy as well as stability. In this review article, all these respects of transgenic plant cell cultures were summarized. In addition, we also discuss the general characteristics of plant cell suspension cultures related with bioreactor design and operation to achieve high productivity in large scale which could be a key to successful commercialization of PMPs.

• 대한미생물학회지
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• 제8권1호
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• pp.1-5
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• 1973

The authors identified 833 Salmonella cultures collected from various parts of the country in 1972. The procedures for the morphological and biochemical tests and for the serological determinations were performed by means of the conventional screening methods recommended by the National Center for Disease Control in U.S.A. The results of the laboratory tests were summerized as follows: 1. Of 833 Salmonella cultures, 1 S. paratyphi A, 1 S. nitra, 1 S. kiel, 1 S. abortusequi, 6 S. paratyphi B, 5 S. abony, 4 S. caledon, 13 S. typhimurium, 2 S. coeln, 1 S. oranienburg, 1 S. thompson, 1 S. bonn, 1 S. gabon, 1 S. colorado, 1 S. richmond, 2 S. berta, 20 S. enteritidis, 1 S. regent, 1 S. london were identified besides 769 cultures of S. typhi. 2. The antibiotics sensitivity tests by means of Ericsson's disc method using seven kinds of antibiotics were carried out, i.e. chloramphenicol, ampicillin, which were widely in common use in the country and the results were compared with that of Salmonella cultures isolated in 1971 as shown in table 4.