• Journal of Plant Biotechnology
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• v.35 no.1
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• pp.81-86
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• 2008

This study describes conditions for plant regeneration from protoplasts-derived from embryogenic callus of satsuma mandarin. Plants were generated via somatic embryogenesis. Protoplasts isolated directly from nucellar callus induced from immature ovule of satsuma mandarin cv. Okitsu (Citrus unshiu Marc.) were cultured in 0.6M $BH_3$ medium. Cell division and plating efficiency were affected by protoplast culture method. The liquid over solid method was the most effective for formation of microcalli. Most of microcalli grew rapidly and transferred onto embryoid formation medium. Optimum embryoid formation medium was MT medium containing 1.5 g/L malt extract, 0.146 M sucrose and the medium for plantlet regeneration was MS medium containing 0.09M sucrose, 1.0 mg/L $GA_3$. No differences were noticed in growth habits and leaf characters such as shape, thickness, and colour between protoplast-derived plants and nucellar seedlings. This plant regeneration system from protoplasts-derived from embryogenic callus provides an alternative way for producing new scion and rootstock cultivar from citrus species which can not be crossed.

• Journal of Plant Biotechnology
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• v.41 no.4
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• pp.223-228
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• 2014

To establish an efficient proliferation and regeneration of PLBs (protocorm-like bodies) of Phalaenopsis plants, a variety of propagation medium types, various concentraions of sucrose as well as liquid and solid type were tested in this study. Further, activated charcoal, citric acid and ascorbic acid were compared whether these agents are suppose to reduce the browning in culture process using PLBs of Phalanopsis plants. With regard to the proper propagation medium, VW medium showed 1.3 ~ 2 times highr than those of other medium in an index of increasing for fresh weight and 50% higher than those of other medium in the frequency of shoot regeneration. However, regarding liquid and solid types of culture, there were no significant differences in the proliferation of PLBs and regeneration of shoots from PLBs. In the experiment for a variety of sucrose concentrations (0 ~ 50 g/l), 10 g of sucrose showed 30 ~ 50% higher than other concentrations in increasing index and 10 ~ 50% higher in the regeneration of shoots from PLBs. Regarding the reduction of browning in tissue culture via PLBs of Phalaenopsis plants, 1 g of activated charcoal showed only 1.5% browning of PLBs cultured. Whereas, other treatments including citric acid and ascorbic acid showed 6 ~ 16% of browning of PLBs. Therefore, activated charcoal was selected as an efficient anti-browning agents for the culture of PLBs in Phalaenopsis plants. Using above-described results can be contibuted to the establishment of mass propagation system using PLBs of Phalaenopsis plants in the future.

• Korean Journal of Food Science and Technology
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• v.10 no.2
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• pp.124-135
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• 1978

This study was undertaken in order to examine the effect of ginger, gerlic and red pepper, usually used as the ingredients of Kimchi, on the growth and acid production of Lact. plantarum ATCC 8014 and Lact. fermenti ATCC 9338 during incubation in the medium containing different amount of each extract. The results obtained are as follows: 1. The effects of ginger extract a. The growth of Lact. plantarum ATCC 8014 and Lact. fermenti ATCC 9338 tended to be stimulated as the amount of extract added into the medium increased in a certain amount (3.64mg soluble solid/ml). b. The pH of the culture medium of Lact. plantarum ATCC 8014 became lower to some degree and acid production tended to be stimulated but acid production of Lact. fermenti ATCC 9338 tended to be suppressed as the amount of extract added in a certain amount (3.64mg soluble solid/ml) increased. 2. The effect of garlic extract a. The growth of Lact. plantarum ATCC 8014 and Lact. fermenti ATCC 9338 tended to be stim ulated as the amount of extract added in a certain amount (31.7 mg soluble solid/ml) increased. b. The acid production of Lact plantarum ATCC 8014 was suppressed (p<0.01) and drop in pH was suppressed (p<0.05) as the amount of extract added in a certain amount increased. In case of Lact. fermenti ATCC 9338, the acid production t ended to be suppressed also. 3. The effects of red pepper extract a. The growth of Lact. plantarum ATCC 8014 and Lact. fermenti ATCC 9338 tended to be stimulated as the amount of extract added in a certain amount (14.5 mg soluble solid/ml) increased.

• Journal of Plant Biotechnology
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• v.5 no.3
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• pp.187-191
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• 2003

This paper reported the establishment of mass production system of adventitious roots of Eleutherococcus sessiliflorus through the shake flask and bio-reactor culture. Induction of adventitious roots was started from the explants of germinated somatic embryos on half-strength Murashing and Skoog (MS) solid medium. The frequency of adventitious root formation was better in the explants comprising the basal hypocotyl parts than root explants alone. Among the different auxins tested (NAA, IBA and IAA), frequency of adventitious root induction was highest on medium with 0.5 mg/L NAA, and produced $16.3\pm1.9$ roots per explant. In shake-flask culture, deletion of $NH_4NO_3$ of MS medium was effective for induction of adventitious root compared with both full and half-strength MS media. Fresh weight increase of induced adventitious roots was performed well in medium with 0.5 mg/L IBA. When adventitious roots produced in shake-flask culture were transferred to 10-liter bioreactor, 5.5 times of fresh weight increase was gained after one month of culture. HPLC analysis revealed that the amount of eleutheroside E and E1 was higher in in vitro cultured adventitious roots than the 3 year-old field cultivated root barks of Eleutherococcus sessiliflorus. The content of eltutheroside B was much lower in adventitious roots than that of field cultivated one.

• Korean Journal of Plant Tissue Culture
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• v.26 no.3
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• pp.157-161
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• 1999

This study was performed to enhance the proliferation rate of Gladiolus 'Topaz' callus. The callus was induced from the cermet tissue explants on MS solid medium with 10 mg/L 2,4-D. In the case of liquid shaking culture, proliferation of the callus was effective in MS medium with 0.05 mg/L 2,4-D at 2$0^{\circ}C$ under 16 hours daylength and in a 100 mL Erlenmeyer flask containing 20 mL of the liquid medium and at 75 rpm in rotation speed of the horizontal shaking culture. Furthermore the callus was also able to be subcultured in the same liquid medium.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.61-61
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• 2003

We have cloned the CGR1 gene encoding glutathione reductase (GR) which catalyzes the reduction of oxidized glutathione (GSSG) to reduced glutathione (GSH) from Candida albicans. The cgr1/cgr1 mutants were not viable when CaMAL2 promoter repressed the CGR1 expression. The growth of the mutants could be partially overcome by thiol compounds such as GSH, dithiothreitol, cysteine, N-acetylcysteine and GSSG. Interestingly, C. albicans with CGR1 overexpressed showed defective hyphal growth on solid medium and attenuated virulence. We have also cloned the GCS1 gene encoding ${\gamma}$-glutamylcysteine synthetase which catalyzes the first step of glutathione biosynthesis. The gcs1/gcs1 mutants were nonviable in minimal defined medium. The growth of the mutants could be resumed by supplementing with GSH, GSSG and ${\gamma}$-glutamylcysteine in the medium. The mutants had increased intracellular D-erythroascorbic acid level up to 2.25-fold when transferred to GSH-free medium. When the mutants were depleted of GSH, they showed typical markers of apoptosis. In conclusion, these results suggest that glutathione is an essential metabolite, and involved in hyphal growth, virulence and apoptosis in C. albicans.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.1
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• pp.85-91
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• 2013

This paper studied surface discharge characteristics by a dielectric constant and diameter of solid dielectrics in $N_2/O_2$ mixture gas. Applied electric field strength at $N_2/O_2$ mixture gas was changed from the dielectric constant and diameter of the solid dielectrics, and insulation performance of the $N_2/O_2$ mixture gas determined surface discharge voltage. In each of the diameter at the solid dielectrics, the surface discharge voltage was increased by lengthening surface distance, whereas increasing rate of the surface discharge voltage was different from gas pressure. Thus, In this paper, main factors of surface discharge are as follows. 1) Insulation performance of $N_2/O_2$ mixture gas, 2) Dielectric constant of solid dielectrics, 3) Surface discharge path. It was clear that the surface discharge voltage depend on the main factors. These results will be applied to useful data for an eco-friendly composite insulation design.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.255-259
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• 2002

To reduce the uncertainty in the calibration of radiation beams, absorbed dose to water for high energy electrons is recommended as the standards and reference absorbed dose by AAPM Report no.51 and IAEA Technical Reports no.398. In these recommendations, water is, defined as the reference medium, however, the water substitute solid phantoms are discouraged. Nevertheless, when accurate chamber positioning in water is not possible, or when no waterproof chamber is available, their use is permitted at beam qualities R$\_$50/ < 4 g/cm$^2$ (E$\_$0/ < 10 MeV). For the electron dosimetry using solid phantom, a depth-scaling factor is used for the conversion of depth in solid phantoms to depth in water, and a fluence-scaling factor is used for the conversion of ionization chamber reading in plastic phantom to reading in water. In this work, the properties, especially depth-scaling factors c$\_$p1/ and fluence-scaling factors h$\_$pl/ of several commercially available water substitute solid phantoms were determined, and the electron dosimetry using these scaling method was evaluated. As a result, it is obviously that dose-distribution in solid phantom can be converted to appropriate dose-distribution in water by means of IAEA depth-scaling.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.535-544
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• 2012

Filtration on horizontal filter medium facing upward is accompanied by sedimentation. When sedimentation phenomenon is not considered, the average specific cake resistance by filtration could be in error more than two times. In the previous paper on this subject, it was insisted that the solid mass fraction of suspension changes in filtration period by sedimentation. But we could not find out the degree of change. At the first half of this paper, the average specific cake resistance measured by permeation will be proved to be exact in several means. The average specific cake resistance conventionally measured by filtration does not give correct results because it uses initial solid mass fraction of suspension. Then we calculated the changed solid mass fraction of suspension due to sedimentation during filtration by the experimental values obtained "filtration-permeation" method. We also determined the solid mass fraction at a certain moment of filtration from the suspension height and a new equation derived in this study. The two results were compared and proven that they almost matched.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.4
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• pp.1-7
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• 2012

The increase of OCC solid content after wet pressing will save drying energy greatly. We applied spacers, which used to increase draining rate and bulk in fiber furnishes, to increase the OCC solid contents. MDF fibers (fibers for making medium density fiberboard) and diatomaceous earth were used as spacers, and added 10% by weight to the OCC fiber furnish. Application of high wet pressing pressure to the mixed furnish of spacers and refined OCC did not deteriorate bulk and drainage rate, but their solid contents were increased to 0.5-1.5% without loss of compressive strength when compared to those of unrefined OCC, which is the furnish normally used for mill commercial practice. It is believed that the spacers caused the rate of solid content increase faster in the mixed furnish with OCC at high wet pressing pressure area than the unrefined OCC furnish did. Little amount of starch addition (0.5%) to the spacers helped to keep the strength properties.