• The Korean Journal of Food And Nutrition
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• v.35 no.6
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• pp.426-434
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• 2022

In this study, the effect of osmotic drying conditions of mangoes on hot air drying was investigated. Four different osmotic agents of 60 Brix, such as S60, SM10, HF80, and SG25, were prepared. Mango slabs were osmotically dried with the agents at a ratio of 1:4 (w/w) for up to 8 hours. SG25 showed the lowest weight reduction and moisture loss during the process. As a result of hot-air drying, all samples showed a high correlation with the Page model (0.9761~0.9997), and the required drying time of all samples that were osmotically dried was reduced compared to the non-osmotically dried group. After hot-air drying, the pH value increased according to the drying temperature. The L, a, and b values and the total polyphenol content also decreased. Through this study, the possibility of osmotic drying was confirmed to increase the efficiency of hot air drying of mangoes, which is expected to contribute to the industrial use of domestic mangoes.

• Journal of Pharmaceutical Investigation
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• v.32 no.4
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• pp.241-258
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• 2002

Such osmotic drug delivery systems are based on osmosis, the diffusion of water transversely from a medium with a low osmotic pressure to a medium with a high osmotic pressure for the controlled delivery of active agents. In this review, U.S. Patents on osmotic drug delivery analyze 261 patents until December 2001. These devices form now a major market of drug delivery products. Because of their advantage and innovate idea, it appears that the future of oral drug delivery mark,εt in Korea is promising.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.348-352
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• 1999

We have intended to accelerate the secretion of human lysozyme(HLY) with permeabilizing agents from the cultivated cells of the recombinant Saccharomyces cerevisiae. The five agents CaCl2, Tween 80, ethanol, Triton X 100, and cetyltrimethylammonium bromide(CTAB) were used as permeabilizing agents. Treatments of the yeast cell with CaCl2, Tween 80, and ethanol were effective to increase the secretion from the yeast cells. Especially, treatment of 10% ethanol increased the extracellular HLY activity by 38.6% at 30oC for 48 h in culture broth. But Triton X 100 and CTAB unexpectedly didn't play a role in increase of HLY secretion. Recovery of a foreign protein by permeabilizing agents is easier than by osmotic shock, and is less expensive than enzymatic digestion.

• Journal of Plant Biotechnology
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• v.4 no.2
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• pp.71-76
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• 2002

In order to achieve repetitive somatic embryogenesis in cacao (Theobroma cacao L.), callus derived from floral tissues were continuously cultured in a medium containing 2,4-D. In 5% of the explants, repetitive somatic embryogenesis was observed after 8 weeks and maintained in a globular stage for several weeks. This is the first report showing repetitive somatic embryogenesis in cacao. The calli were bombarded with a plasmid containing $\beta$-glucuronidase (gus) as reporter gene. Two week old calli showed the high average number of cells expressing the us gene. The effect of osmotic agents (mannitol, sorbitol and sucrose) on gene expression was evaluated. Pre-treatment during 16 h with 0.25 M mannitol revealed an improvement in gene expression. The potential utilization of the repetitive embryogenesis, combined with osmotic treatment, is discussed as an alternative to achieve stable transgenic cacao plants.

• Polymer(Korea)
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• v.38 no.5
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• pp.626-631
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• 2014

Water purification requires a large amount of energy that can cause pollution problems. For this reason, forward osmosis (FO) has attracted intense interest that required a relatively low amount of energy for water purification. The forward osmosis has a serious problem that it needs drawing agents creating osmotic pressure to extract water from contaminated water. In this study, a copolymer of zwitterionic moiety and an interpenetrating polymer network (IPN) hydrogel based on thermo-responsive polymer hydrogel, poly(N-isopropylacrylamide) (PNIPAM) were prepared and attached on FO membranes, which successfully played the role of drawing agents. In the copolymer hydrogel, its swelling ratio was improved, but thermo-sensitivity was decreased. The swelling ratio and thermo-sensitivity of IPN hydrogel was lowered. We could confirm that swelling ratio is related to osmotic pressure.

• Journal of Microbiology and Biotechnology
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• v.17 no.9
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• pp.1504-1512
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• 2007

The fpr gene, which encodes a ferredoxin-$NADP^+$ reductase, is known to participate in the reversible redox reactions between $NADP^+$/NADPH and electron carriers, such as ferredoxin or flavodoxin. The role of Fpr and its regulatory protein, FinR, in Pseudomonas putida KT2440 on the oxidative and osmotic stress responses has already been characterized [Lee at al. (2006). Biochem. Biophys. Res. Commun. 339, 1246-1254]. In the genome of P. putida KT2440, another Fpr homolog (FprB) has a 35.3% amino acid identity with Fpr. The fprB gene was cloned and expressed in Escherichia coli. The diaphorase activity assay was conducted using purified FprB to identify the function of FprB. In contrast to the fpr gene, the induction of fprB was not affected by oxidative stress agents, such as paraquat, menadione, $H_2O_2$, and t-butyl hydroperoxide. However, a higher level of fprB induction was observed under osmotic stress. Targeted disruption of fprB by homologous recombination resulted in a growth defect under high osmotic conditions. Recovery of oxidatively damaged aconitase activity was faster for the fprB mutant than for the fpr mutant, yet still slower than that for the wild type. Therefore, these data suggest that the catalytic function of FprB may have evolved to augment the function of Fpr in P. putida KT2440.

• Journal of Forest and Environmental Science
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• v.34 no.3
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• pp.224-234
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• 2018

An efficient method to select drought tolerant Korean native plants using in vitro culture system was established in this study. While the plant growths and root inductions of each plant were proportionately affected by concentrations of mannitol on in vitro culturing seven plant species to test tolerance to osmotic stress, growth index (GI) and number of root induction of Chrysanthemi zawadskii var. latilobum and Dianthus chinensis var. semperflorens plantlets were higher than the others in 125mM mannitol. In test with polyethylene glycol (PEG), plantlets of C. zawadskii var. latilobum and D. chinensis var. semperflorens showed higher GI and number of root induction than the others in 33.3mM. On testing whether the well grown plants under osmotic stress are tolerant to virtual drought stress, there were significant differences in the withering rates of C. zawadskii var. latilobum and D. chinensis and those of were Aster yomena and Centaurea cyanus after 12 days without watering. It was found that significantly lower stomata numbers were shown in both drought tolerant plants than the sensitive plants. Averages of the stomata circumferences and the stomata area in the plantlets of the tolerant species were larger than those of the sensitive plants D. chinensis var. semperflorens showed the lowest transpiration level per unit area. The highest stomatal area per unit area was found in C. zawadskii, followed by D. chinensis var. semperflorens, Aster yomena and C. cyanus. In conclusion, C. zawadskii var. latilobum and D. chinensis var. semperflorens were more tolerant to drought than other two species. Furthermore in vitro selection was successfully used to screen drought tolerance species of native plant species.

• Journal of Plant Biotechnology
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• v.50
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• pp.89-95
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• 2023

In order to investigate the effect of carbon sources on somatic embryogenesis and cotyledon number variations in carrot, embryogenic callus were cultured in the medium supplemented with various concentrations of sucroseor glucose, and with combination of 2% sucrose and various concentrations of mannitol or sorbitol. The maximum number of somatic embryos formed per flask (1,555.70) was obtained in the medium supplemented with 2% sucrose rather than glucose alone or a combination of mannitol or sorbitol and 2% sucrose, and the number of somatic embryos was decreased with the increasing of mannitol or sorbitol concentration. The frequencies of somatic embryos with two cotyledons were 35.14% for sucrose, 19.88% for glucose, 32.55% for mannitol + 2% sucrose, and 38.59% for sorbitol + 2% sucrose, respectively, and the frequencies of abnormal somatic embryos having 3 or more cotyledons were 64.86% for sucrose, 80.12% for glucose, 67.44% for mannitol + 2% sucrose, and 61.41% for sorbitol + 2% sucrose, respectively. Particularly, the frequency of somatic embryos with two cotyledons (59.16%) was the highest in the 2% sucrose medium compared to the frequency of abnormal somatic embryogenesis with three or more cotyledons, and the frequency gradually decreased with increasing concentration of glucose, mannitol or sorbitol. According to these results, it was found that the ratio of abnormal somatic embryo was higher than the normal somatic embryo in carrot, and was shown that somatic embryogenesis and the cotyledon number was affected by the concentrations of sucrose, glucose as carbon source, and mannitol and sorbitol as osmotic agents in culture medium.

• Molecules and Cells
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• v.22 no.2
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• pp.203-209
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• 2006

TBP (TATA-binding protein)-related factor 2 (TRF2) regulates transcription during a nuber of cellular processes. We previously demonstrated that it is localized in the cytoplasm and is translocated to the nucleus by DNA-damaging agents. However, the cytoplasmic localization of TRF2 is controversial. In this study, we reconfirmed its cytoplasmic localization in various ways and examined its nuclear migration. Stresses such as heat shock, redox agents, heavy metals, and osmotic shock did not affect localization whereas genotoxins such as methyl methanesulfonate (MMS), cisplatin, etoposide, and hydroxyurea caused it to migrate to the nucleus. Adriamycin, mitomycin C and ${\gamma}$-rays had no obvious effect. We determined optimal conditions for the nuclear migration. The proportions of cells with nuclei enriched for TRF2 were 25-60% and 5-10% for stressed cells and control cells, respectively. Nuclear translocation was observed after 1 h, 4 h and 12 h for cisplatin, etoposide and MMS and hydroxyurea, respectively. The association of TRF2 with the chromatin and promoter region of the proliferating cell nuclear antigen (PCNA) gene, a putative target of TRF2, was increased by MMS treatment. Thus TRF2 may be involved in genotoxin-induced transcriptional regulation.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.216-216
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• 2017

Primed seeds germinate faster and uniformly, since these have already started imbibition and metabolism requiring to complete germination. Several factors such as solution composition, osmotic potential, and treatment duration affect seed priming response. Water potentials of priming solution and germination response of primed seed were investigated to clarify the effects different inorganic salt types and the duration. Pepper seeds were primed in osmotic solutions that were osmotic potential ranged -1.54 to -0.45 MPa in an aerated solution of polyethylene glycol 8000 (PEG; 17%, 22%, 27%), and inorganic salt solution of $KNO_3$, $K_2SO_4$, and $Na_2SO_4$ (100, 200, 300mM) in aerated condition. The seeds were treated at $20^{\circ}C$ for 4, 6 day (D) and stepwise duration combined concentration of 100mM (2 or 4 days) and 300mM(2 or 4days). After soaking treatment, seeds were washed with distilled water and then were dried to approximately 6% moisture content in dry chamber at $25^{\circ}C$. The germination of seed was characterized by ISAT rules at $20^{\circ}C/30^{\circ}C$ and $15^{\circ}C$. Total germination percentage (GP), mean germination time (MGT), germination uniformity (GU), germination rate (GR), and health seedling percent (HS) were calculated on the germinated seed in a 14-day period. Seed water potential (${\psi}$) was correlated with water potential of priming solution ($r^2=0.84$). The effect of seed priming on germination varies with inorganic salt and organic agents (PEG). Germination percentage (GP, 77 and 73%), GR (21.3 and $19.4 %{\cdot}day^{-1}$), and HS (58 and 52 %) was greatest and lowest MGT (4.2 and 4.8 day) when they were primed in 100mM $K_2SO_4$ (${\psi}=-0.45MPa$), and 100mM $KNO_3$ (${\psi}=-0.52MPa$) for 6 days compared to untreated control (67% GP, $19.7%{\cdot}day^{-1}\;GR$, 18% HS, and 10.8 day MGT) in $15^{\circ}C$ chamber. Water potential less then -1.2MPa of osmotic solution resulted lower GP, GR and HS and in $K_2SO_4$ and $KNO_3$. However, stepwise treatment of water potential that changed solution as 100mM for 4 D + 300mM for 2 D or 300mM for 4 D + 100mM for 2 D) were not better than single concentration alone in germination characteristics.