• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.221-224
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• 2001

Effect of hyperosmotic pressure on growth of recombinant Chinese hamster 。 vary cells and Erythropoietin (EPO) production was investigated. Cells were cultivated in batch modes at various osmolalities. When the osmolality increased from 314 to 463mOsm/Kg, specific EPO productivity (qp) was increased up to 1.6-fold but cell growth was inhibited. EPO has a complex oligosaccharide structure that plays an important role in biological activity in vivo. To investigate the influence of hypoerosmotic pressure on the glycosylation, structural analysis of oligosaccharide was calTied out. Recombinant human EPO was produced by CHO cells grown under various osmotic pressure and purified from culture supernatants by heparin-sepharose affinity column and immunoaffinity column. N-linked oligosaccharides were released enzymatically and isolated by paper chromatography. The isolated oligosaccharides were labeled with fluorescent dye, 2-aminobenzamide and analyzed with MonoQ anion exchange chromatography and GlycosepN amide chromatography for the assignment of GU (glucose unit) value. Glycan analysis by HPLC showed that neutral (asialo) oligosaccharide was increased slightly with an increase in osmolality. In portion of sialylated glycan, total relative amount of mono- and di-sialyated glycan was increased but that of tri- and tetra-sialylated glycan decreased as osmolality was increased.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.697-700
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• 2003

젓갈에서 분리한 유용 유산균인 Lactococcus lactis NK24, Lactobacillus plantarum NK181, 효모인 strain HW161를 대상으로 항산화능과 콜레스테롤 저해능을 검토 하였다. 항산화능을 조사한 결과, DPPH의 free radical 소거능은, strain HW161, Lactococcus lactis NK24, Lactobacillus plantarum NK181 순서로 나타났다. TCA를 이용한 실험의 결과, 과산화물질 저해능을 확인할 수 있었다. 또한, 콜레스테롤 저하 실험의 결과 는 strain NK181이 가장 우수하게 나타났다. 따라서 본 실험에서 사용된 균주들은 프로바이오틱 생균제로서의 가능성을 보여 주었다.

• 한국식품위생안전성학회지
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• 제10권2호
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• pp.65-71
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• 1995

Bacteriocins from lactic acid bacteria have attracted much attention in recent years because of their useful worth in increasing safety and extending shelf life of foods. These substances show an inhibitory effect against some food spoilage bacteria and food-borne pathogens. The inhibitory effect fo the bacteriocin produces by lactic acid bacteria against Listeria monocytogenes(L. monocytogenes) was examined in this study. The culture supernatants of 5 kinds of bacteria among the 10 kinds of testes lactic acid bacteria had the inhibitory activity against Listeria sp., various Gram positive and Gram negative bacteria. Bacteriocin produced by Lactobacillus plantarum(Lact. plantarum) LMG 7945 was the most active toward L. monocytogenes. Bacteriocin production of the Lact. plantarum LMG 7945 cultured on MRS broth was increased late logarithmic phase over early stationary phase. This bacteriocin was stable at heat treatment and acidic pH relatively; The activity was retained after heating at 121$^{\circ}C$ for 15min and was active in the pH range of 2~4 but was lost above pH 5.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1368-1376
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• 2005

Pseudomonas aeruginosa produces a variety of bacteriocidal substances including pyocins that are active against the same species, but their physiological roles are relatively unknown. Here, we profiled the bacteriocidal activities in the culture supernatants of various P. aeruginosa isolates and describe the competitive growth advantages of strains PAO1 and PA14 over some strains including PAK, which are sensitive to their bacteriocidal activities. These findings suggest that the factors governing the production of pyocins and the resistance to them play important roles in controlling P. aeruginosa populations in its local environments.

• Journal of Microbiology and Biotechnology
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• 제1권4호
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• pp.256-260
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• 1991

In B. subtilis, $\alpha$-amylase synthesis is regulated by amyR located directly on the upstream of amyE. Three different amyR alleles have been reported, amyR1, amyR2 and amyR3. Strains bearing the gra-10 mutation which confers derepression for catabolite repression has GlongrightarrowA transition mutation at ＋5 of amyR1. S1 nuclease mapping demonstrated that transcription initiated at 8 bases downstream from the -10 region of putative E$\sigma^{A}$ promoter P1 in amyR1 and gra-10. In amyR2, the major transcription initiatd at the same place and the minor, 10 bases downstream from -10 of P2. The transcript from P2 contributed approximately 15-20% of total amyE mRNA. S1 nuclease protection experiment indicated that amyE mRNA levels corresponded to the rate of synthesis assumed by specific activities of $\alpha$-amylase in culture supernatants, suggesting that $\alpha$-amylase synthesis is regulated at the level of transcription.n.

• Journal of Nutrition and Health
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• 제26권4호
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• pp.379-389
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• 1993

Several studies have shown that extracts from yellow-green vegetables reveal antitumor activities. In the present study we investigated the effect of phytol in order to elucidate the immunological mechanism of antitumor activity of this substance. The results obtained from the experiment as follows: 1) Phytol showed cytotoxic effect on sarcoma 180 cells in vitro. 2) When phytol was injected into the peritoneal cavity of mice transplanted with sarcoma 180 cells, the average survival time (24.0 days) tended to increase as compared with the nontreated control (19.2 days). 3) When sarcoma 180 cells were injected subcutaneously into the right groin of mice, and then phytol was injected into the peritoneal cavity, the tumor inhibition ratio was 33%. 4) The natural killer(NK) cell activity was significantly augmented by phytol in vitro and in vivo. Similar augmentations of NK cell activity were obtained with culture supernatants of phytol exposed spleen cells and peripheral blood mononuiclear cells. 5) Phytol on the macrophage from peritoneal cavity showed a higher effectiveness in vivo than in vitro. These results indicate that phytol shows the inhibitory effect for growth of sarcoma 180 cells in vitro, also it can augment macrophage and NK cell activities in vivo.

• BMB Reports
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• 제28권1호
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• pp.46-50
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• 1995

Three kinds of mouse tumor necrosis factor (TNF), which have molecular weights of 35 kDa, 45 kDa, and 18 kDa on SDS-PAGE, were partially purified from serum-free culture supernatants of mouse peritoneal macrophages induced with lipopolysaccharide. Analysis of the native molecular weights by gel filtration indicated that the 18 kDa and 45 kDa TNFs aggregate into 50 kDa and 100 kDa molecules, respectively, while the 35 kDa TNF is contained in high molecular weight aggregates of approximately 200 kDa. The three kinds of cytotoxic factors all elicited tumor reducing responses.

• Journal of Microbiology and Biotechnology
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• 제9권6호
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• pp.877-880
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• 1999

Over 50 morphologically distinctive soil Streptomyces were isolated from various Jocations in the Yongin area in Korea and visually screened for dye-decoloring activities on an agar plate. Two Streptomyces species (AD001 and ND002) showed strong dye-decoloring activities on the plate containing congo-red and new-fuchin dyes, respectively. Also, the liquid culture supernatants of these species showed 2,4-dicholophenol (DCP) oxidation activities only in the presence of hydrogen peroxide, a characteristic of Actinomycetes lignin-peroxidase (ALiP)-P3 isoform found in dye-degrading S. viridosporus T7A and S. badius 252. Based on their dye-decoloring capabilities and the 2,4-DCP oxidation kinetic data, it is suggested that these Streptomyces secrete not-yet-characterized extracelluar enzyme(s), whose activities are very similar to the ALiP-P3 enzyme.

• 대한수의학회지
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• 제39권2호
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• pp.311-317
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• 1999

Pathogenic effects of 29 different porcine reproductive and respiratory syndrome(PRRS) virus isolates were investigated in swine tracheal ring(STR) cultures by examining their effects on the ciliary activity of STR. Inhibition of ciliary movement and destruction of the tracheal epithelium were seen between 72 and 96 hours postinoculation(PI). Virus replication was demonstrated by examining viral infectivity of the supernatants from the STR cultures. PRRS virus antigen in macrophages was detected by a streptavidin-biotin complex(ABC) immunoperoxidase method. Of the 29 PRRS virus isolates, 8 isolates were classified into pathogenic, and the remaining 21 isolates were determined as mildly pathogenic or apathogenic viruses. These results suggest that STR examination may be used as a method for predicting pathogenic variability of PRRS virus isolates.

• 약학회지
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• 제45권6호
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• pp.708-714
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• 2001

Many studies have provided evidences that hepatitis B surface antigen (HBsAg) including preS region could be an ideal candidate for a new hepatitis B virus (HBV) vaccine with higher efficacy. We established CHO cell lines, IY-CHO-2 and IY-CHO-11 expressing high levels of HBsAg containing preS2 and S protein by stable transfection method. These cell lines expressed the correct size (about 1 kb in length) of HBsAg mRNA as expected. The purified protein from the culture supernatants of the clones showed the same sizes as those expressed in native hepatitis B virus (24 kDa, 27 kDa, 34 kDa and 36 kDa). Antibody productivity of CHO-derived HBsAg protein at lower dose challenge was higher than the protein containing S region alone expressed in yeast system. These results indicate that CHO-derived HBsAg protein containing preS2 and S region can be effectively used for a better immune response as a HBV vaccine.