• Membrane Journal
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• v.33 no.6
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• pp.390-397
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• 2023

Conventional extraction methods for polyhydroxybutyrate (PHB), a sustainable alternative to petroleum-based plastics, cause a decrease in molecular weight and a change in properties. In this work, we developed a method to extract PHB accumulated in microorganisms by physical disruption through filtration using a spiked carbon nanotube (CNT) membrane with functionalized CNT. In addition, filtration of the PHB-containing microbial solution was performed to confirm PHB extraction, which was found to be 4% more efficient than chloroform, the most used extraction method. These results indicate that the spiked CNT membrane has potential in the bioplastics recovery process.

• Korean Journal of Food Science and Technology
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• v.11 no.4
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• pp.242-248
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• 1979

To detect proper lytic assay conditions of the crude zumolyase from Arthrobacter luteus, effets of the various factors involved in the lytic system of Sacchromyces sake cultured with shaking in the malt extracts medium were investigated. The results are summarized as follows : 1. The susceptibilities of viable cells of S. sake from logarithmic growth phase to the lytic enzmye were much greater than those of the cells in lag and stationary phases. The cells cultured for 18 hr were the most susceptible to the enzyme. 2. Lytic activity of the enzyme toward the viable cells of S. sake was very low. It was, however, enhanced 4 folds of more by the pretreatment of the cells with 0.05 M sodium sulfite. 3. Lytic activity of the enzyme toward commercial baker's yeast cells was negligible, and the effect of sodium sulfite on the lysis of the cells also was nothing but a little. 4. The lyophilized cells of the baker's yeast showed more susceptibility to the lytic enzyme than viable cells of the yeast. No definite effect of sodium sulfite on the lysis of the lyophilized cells, however, was observed either baker's yeast of S. sake. 5. It appeared that the relationship between the reaction rate and the enzyme concentration on the lysis of the yeast cell walls followed enzyme kinetic theory, but one between the reaction rate and concentration of the yeast cells as substrates showed different pattern from that in enzyme kinetic theory. 6. After the preparation of crude zymolyase was kept at $7^[\circ}C$ for 10 days in the 0.05 M phosphate buffer, pH 7.5, the remainning lytic activity was about 80 %.

• Journal of Embryo Transfer
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• v.18 no.3
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• pp.171-178
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• 2003

This study was conducted to investigate the effect of electric fusion methods on cell fusion rate and embryo development by somatic cell nuclear transfer in Korean Native Cattle. The KNC ear cell was cultured in vitro for confluence in serum starvation condition(DMEM＋0.05％ FBS) for cell confluence. The zona pellucida of IVM oocytes were partially dissection using micro pipette. Ear cells were transferred into an enucleated oocyte. The reconstructed embryos were electrically fused with Zimmermann Cell Fusion Medium(ZCFM). Nuclear transfer embryos were activated with a combination of 10${\mu}{\textrm}{m}$ calcium ionophore(5 min) and 2.0mM 6-DMAP(3 hr). The activated embryos were cultured in CR1 -aa medium contains 0.3％ BSA or 10％ FBS at 37$^{\circ}C$, 90％ $N_2$, and 5％ $CO_2$in incubator for 6 days. The fusion rates were 51.6％(chamber) and 68.9％(needle), respectively and there were significantly difference between the fusion method(P<0.05). But, lysis rates were not significantly different(10.7％, 11.5％), respectively. The cleavage rates were significantly different between the chamber method(73.2％) and needle method(80.3％), respectively(P<0.05). The rates of early embryos(2∼4cells) and blastocysts of chamber and needle methods were 54.1％, 61.1％ and 18.4％, 26.3％ respectively, and needle method was significantly higher than chamber method(P<0.05). But, morulae formation rate were not significantly differences between the chamber(6.7％) and needle(6.2) method(P <0.05). These result suggest that electric fusion of needle method was to be profitable for nuclear transfer embryo fusion rate, blastocyst formation rate and reduce of oocyte lysis.

• The Journal of Internal Korean Medicine
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• v.29 no.4
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• pp.1075-1082
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• 2008

Objectives : The purpose of this experiment is comparing the difference on natural killer cell activity through Korean red ginseng and Chinese red ginseng by $^{51}Cr$ release assay. Methods : Thirty rats were equally divided into a Korean red ginseng group, a Chinese red ginseng group and a control group. Korean and Chinese red ginseng were administrated to the rats at 200mg daily for a weak, while 0.9% normal saline was given to the control. Percent specific lysis (PSL) and lytic units (LU) were calculated from spleen cells by $^{51}Cr$ release assay. Results : Percent specific lysis of the Korean red ginseng group was significantly higher than that of the control in the ratio of 100:1, effector cell:target cell (p<0.05). Percent specific lysis of Korean red ginseng group was also significantly higher than that of the Chinese red ginseng group in the ratio of 25:1, effector cell:target cell (p<0.05). Chinese red ginseng showed no effect on NK cell activity. Conclusions : These findings suggest that Korean red ginseng improves immunologic function and shows superior effects than Chinese red ginseng.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.4
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• pp.401-408
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• 1985

The yeast cell wall lytic action of the alkaline AL-protease, which was found out of the crude Zymolyase that a kind of yeast cell wall lytic $endo-{\beta}-1$, 3-glucanase produced from Arthrobacter luteus, was investigated with the viable cells of S. sake and it's cell wall preparation. AL-protease on the lysis of the viable yeast cells showed very low activities with the alone, but the lytic activities were highly increased with the combination of AL-protease and Zymolyase. On the stepwise treatment of the viable yeast cells with AL-protease and Zymolyase, the cells were lysed highly only by the course having a treatment with Zymolyase after pretreatment with AL-protease. Thus synergistic action of AL-protease was not observed with any some commercial enzymes, known as a type of alkaline and serine protease such as AL-protease, and was also found to be affected greatly by the culture conditions and species of the yeast tested. AL-protease caused the release of some peptide and a lot of sugar from the cell wall preparation, but could not lysed the cell wall more than 66%. Whereas Zymolyase could lysed the cell walls almost completely with alone. On the basis of these results, the synergistic action of AL-protease on the lysis of S. sake cells is hypothesized that at first AL-protease bind to the yeast cell surface layer consisting of mannan and protein, and then changes their conformation to facilitate the penetration of Zymolyase from the outside to the inside framework layer constituted of alkali insoluble ${\beta}-1,\;3-glucan$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.4
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• pp.472-476
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• 2008

The possibility of DNA comet assay as a rapid method for screening the irradiated vegetables and grains was evaluated. Vegetables (spring onion, garlic, and tomato) irradiated at $0{\sim}3$ kGy and grains (rice flour and black soybean) irradiated at $0{\sim}9$ kGy were used as samples. Optimum DNA comet assay conditions, such as elution, sedimentation of suspension, and lysis time of cell, were established. The optimum conditions for vegetables were 10 min for the elution time, 0 min for the sedimentation time, and 5 min for the lysis time. The optimum conditions for grains were 15 min for the elution time, 60 min for the sedimentation time, and 30 min for the lysis time. For the food application of DNA comet assay, it was possible to screen various food samples irradiated at the following doses: spring onion at 2 kGy, garlic at 3 kGy, tomato at 1 kGy, rice flour at 9 kGy, and black soybean at 3 kGy. Each sample showed different forms and sizes in DNA comet. Therefore, further studies on various methods using comet shape, concentration, or area in DNA comet assay are necessary.

• Applied Microscopy
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• v.12 no.1
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• pp.69-73
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• 1982

The phages of Bacillus subtilis SNU 816 were observed by electron microscope with their host. The results are as follows; The phage had hexagonal head, contractile tail sheath and base plate with six tail fibers. During the lysis of bacteria due to attack of phage, dissolution of flagella were initiated from distal end of flagella.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.564-564
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• 2005

• Journal of fish pathology
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• v.19 no.3
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• pp.285-288
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• 2006

The respiratory burst activity of tilapia (Oreochromis mosambicus) phagocytes agaisnt Edwardsiella tarda ghosts produced by gene E mediated lysis was investigated. Stimulation with E. tarda ghosts (ETG) showed markedly higher respiratory burst activity than that with formalin killed E. tarda (FKC) in phagocytes. This result may suggest that ETG can induce effective cellular immune responses in fish.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.206.2-207
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• 2003

The immunostimulatory and host resistance effects of the Platycodon grandiflorum A. DC, changkil (CK) and inulin (CKI) isolated from CK were investigated in rats. SD rat were exposed to CK or CKI by gavages for 7days and isolated peritoneal macrophages and splenocyte were used for these studies. CK and CKI significantly enhanced peritoneal macrophages activities such as ROS production and phargocytosis. (omitted)