• Journal of Microbiology and Biotechnology
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• v.4 no.2
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• pp.95-101
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• 1994

The effects of glycine on cell growth and L-omithine production were investigated in shake-flask and jar fermentor cultures of a citrulline auxotrophic mutant, Brevibacterium ketoglutamicum BK 1046. In the shake-flask culture, the optimal concentration of glycine for L-ornithine production was found to be 20 g/l. In the jar fermentor culture with the glycine at an initial concentration of 20 g/l, L-ornithine production increased by 28%, compared to that of the culture with no glycine added. 37 g/l of L-ornithine was produced when additional feeding of glycine (5 g/l) was made. This was a significant improvement in L-ornithine production compared to that (ca. 24 g/l) of the corresponding batch culture conducted without glycine. According to the stoichiometric analysis with the batch fermentation results, the experimental and theoretical L-ornithine yields based on the glucose consumption were 0.24 and 0.59, respectively. This indicates that the performance of L-ornithine fermentation can further be improved by the supplementation of glycine and the development of a mutant strain possessing a higher growth yield.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.600-603
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• 2000

DNA chip containing 207 E. coli genes related to important metabolisms such as (TCA cycle, glycolysis, fermentation and etc) were used to carry out a comprehensive investigation of the change in metabolism and physiology during high cell density culture of E. coli by fed-batch cultivation.

• Korean Journal of Veterinary Service
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• v.35 no.4
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• pp.289-294
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• 2012

Mycoplasmas are highly fastidious bacteria, difficult to culture and slow growing. Infections with Mycoplasma species can cause a variety of problems in living organisms and in vitro cell cultures. In this study, we investigated the usefulness of a genus-specific consensus PCR analysis method to detect Mycoplasma species. The developed consensus primer pairs MycoF and MycoR were designed specifically to amplify the 16S ribosomal RNA gene (rRNA) of Mycoplasma species by the optimized PCR system. The developed consensus PCR system effectively amplified 215 bp of Mycoplasma genus-specific region of 16S rRNA. In conclusion, we recommend this consensus PCR for monitoring Mycoplasma species in animals, human and cell culture system.

• Journal of Biomedical Engineering Research
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• v.30 no.2
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• pp.103-112
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• 2009

Neuron-on-a-Chip technology is based on advanced neuronal culture technique, surface micropatterning, microelectrode array technology, and multi-dimensional data analysis techniques. The combination of these techniques allowed us to design and analyze live biological neural networks in vitro using real neurons. In this review article, two underlying technologies are reviewed: Microelectrode array technology and Neuronal patterning technology. There are new opportunities in the fusion of these technologies to apply them in neurobiology, neuroscience, neural prostheses, and cell-based biosensor areas.

• Journal of Plant Biology
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• v.9 no.1_2
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• pp.1-6
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• 1966

Using the Chlorella cells which had been uniformly labeled with $^{32}P$, the distribution of phosphorus in various fractions of cell material was investigated. Uniformly $^{32}P$-labeled Chlorella cells were further grown in a P-free medium, and some protions of the cells were taken out at intervals during the culture, and subjected to analyze the contents of $^{32}P$ in various fractins of the cell constituents. 2. Analysis of the $^{32}P$-labeled Chlorella cells showed that the highest in P-content was the fraction of RNA followed by those of lipid, RNA-polyphosphate complex, acid-insoluble polyphosphate, acid-soluble polyphosphate, DNA and protein. 3. During the culture of $^{32}P$-labeled Chlorella cells in a P-free medium, amounts of phosphate in DNA, protein and lipid fractions increased, while the P-contents in the fraction of RNA-polyphosphate complex decreased as well as those of acid-insoluble polyphosphate and acid-soluble polyphosphate fractions. 4. It was inferred that phosphorus used in the syntheses of DNA and protein was taken from polyphosphates of the cells, and RNA-polyphosphate complex would play an important role as a phosphate pool.

• Journal of Genetic Medicine
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• v.11 no.2
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• pp.43-48
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• 2014

Chorionic villus sampling has gained importance as a tool for early cytogenetic diagnosis with a shift toward first trimester screening. First trimester screening using nuchal translucency and biomarkers is effective for screening. Chorionic villus sampling generally is performed at 10-12 weeks by either the transcervical or transabdominal approach. There are two methods of analysis; the direct method and the culture method. While the direct method may prevent maternal cell contamination, the culture method may be more representative of the true fetal karyotype. There is a concern for mosaicism which occurs in approximately 1% of cases, and mosaic results require genetic counseling and follow-up amniocentesis or fetal blood sampling. In terms of complications, procedure-related pregnancy loss rates may be the same as those for amniocentesis when undertaken in experienced centers. When the procedure is performed after 9 weeks gestation, the risk of limb reduction is not greater than the risk in the general population. At present, chorionic villus sampling is the gold standard method for early fetal karyotyping; however, we anticipate that improvements in noninvasive prenatal testing methods, such as cell free fetal DNA testing, will reduce the need for invasive procedures in the near future.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.2
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• pp.114-125
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• 2002

This study was designed to evaluate the influence of fibroblasts or connective tissue from mouse oral mucosa on differentiation of neonatal mouse calvaria-derived osteoblasts and mineralization of bone nodules. Primary cell cultures from mouse calvarial osteoblasts and 2-4 passaged fibroblasts from oral mucosa were co-cultured in monolayer cultures, devided into 6 experimental group according to cell density or cell confluency. Osteoblasts were also co-cultured with fibroblasts in $Transwell^{(R)}$ culture plate with different co-cultured period according to osteoblast differentiation. The alkaline phosphatase activity were measured in monolayer cultures and cultures using $Transwell^{(R)}$. The mineralized bone nodules were presented by Von Kossa staining and density of mineralized nodules was measured by image analysis. The connective tissues with or without osteoblast seeding were cultured and examined histologically by Von Kossa and Trichrome Goldner staining. The results were as follows; 1. Prolonged maturation of matrix and delayed mineralization of bone nodules were resulted in monolayer cultures. 2. Co-culture of fibroblast with osteoblast using $Transwell^{(R)}$ during osteoblast proliferation stage stimulated proliferation of osteoblasts and increased alkaline phosphatase activity and mineralization of bone nodules. 3. Co-culture of fibroblast with osteoblast using $Transwell^{(R)}$ during matrix mineralization stage decreased and delayed mineralization of bone nodules. 4. In vitro cultured connective tissue with osteoblast seeding resulted in proliferation of osteoblasts and matrix formation with mineralization.

• Microbiology and Biotechnology Letters
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• v.30 no.1
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• pp.63-67
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• 2002

Bifidobacterium strain was isolated from the feces of brast fed infants. The isolated strain was identified as Bifidobacterium longum by 16S rRNA sequence analysis and named as Bifidobacterium SH2. The MRS medium was modified to obtain high density cells of Bifidobacterium SH2. The optimal medium was determined to be 50 g/L lactose, 10 g/L beef extract, 10 g/L peptone, 5 g/L yeast extract, 7 g/L sodium acetate, 2 g/L ammonium citrate, 2 g/L disodium phosphate,1 g/L tween 80, 0.2 g/L MnSO$_4$ and 0.5 g/L L-cysteine. The pH and temperature were optimized as 5.0 and $37^{\circ}C$, respectively. Through out the optimization of medium composition and culture conditions, the dry cell weight and viable cell count were 2.5 times and 1.8 times higer than those in MRS medium, respectively.

• Clinical and Experimental Reproductive Medicine
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• v.49 no.4
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• pp.259-269
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• 2022

Objective: Animal-free scaffolds have emerged as a potential foundation for consistent, chemically defined, and low-cost materials. Because of its good potential for high biocompatibility with reproductive tissues and well-characterized scaffold design, we investigated whether polyglycolic acid (PGA) could be used as an animal-free scaffold instead of natural fibrin-agarose, which has been used successfully for three-dimensional human endometrial cell culture. Methods: Isolated primary endometrial cells was cultured on fibrin-agarose and PGA polymers and evaluated various design parameters, such as scaffold porosity and mean fiber diameter. Cytotoxicity, scanning electron microscopy (SEM), and immunostaining experiments were conducted to examine cell activity on fabricated scaffolds. Results: The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay and SEM results showed that endometrial cells grew and proliferated on both scaffolds. Immunostaining showed cytokeratin and vimentin expression in seeded cells after 7 days of culture. On both scaffolds, an epithelial arrangement of cultured cells was found on the top layer and stromal arrangement matrix on the bottom layer of the scaffolds. Therefore, fibrin-agarose and PGA scaffolds successfully mimicked the human endometrium in a way suitable for in vitro analysis. Conclusion: Both fibrin-agarose and PGA scaffolds could be used to simulate endometrial structures. However, because of environmental and ethical concerns and the low cost of synthetic polymers, we recommend using PGA as a synthetic polymer for scaffolding in research instead of natural biomaterials.

• Journal of Plant Biotechnology
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• v.3 no.1
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• pp.1-5
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• 2001

Traditional culture technology of medicinal plants mainly depends on the field culture, which has many problems. With progress of modern culture technology, it has become possible to produce valuable secondary metabolites from medicinal plants. In this paper, we discuss about the pigment and saikosaponin production from too medicinal plants, Carthamus tinctorius and Bupleurum falcatum, through bioreactor culture system. A two-stage bioreactor culture system was established for the production of yellow and red pigments and saikosaponins by cell suspension cultures of Carthamus tinctorius and Bupleurum falcatum. In Carthamus tinctorius, balloon type airlift bioreactors and column type airlift bioreactors were employed for the tell culture and for the pigment production, respectively. The greatest pigment production was obtained on White medium supplemented with 4 mg/L kinetin, high levels of sucrose concentration and photosynthetic photon flux. In Bupleurum falcatum, adventitious roots were cultured in balloon type airlift bioreactors and the root growth was greatest on SH medium containing 5 mg/L IBA and 0.2 mg/L kinetin. HPLC analysis showed that the contents of main active saikosaponins a, c, and d in adventitious roots were almost the same as those in field cultured root.