• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.408-411
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• 2005

The green fluorescent protein (GFP) from the jellyfish aequorea and its fluorescent homologs from Anthozoa corals have become invaluable tools for imaging of cells and tissues. In this study various fluorescent protein such as green fluorescent protein (GFP), yellow fluorescent protein (YFP) and red fluorescent protein (RFP) have been expressed in Escherichia coli. Growth of recombinant cells and production of fluorescent proteins were investigated in shake flasks. Some characteristics of fluorescent proteins was also studied.

• Journal of Microbiology and Biotechnology
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• v.5 no.4
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• pp.234-237
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• 1995

Production of new flavanol derivatives with cytotoxic activity, gericudranin A and B, was studied by using hairy root cultures of Cudrania tricuspidata. Schenk and Hildebrandt (SH) medium was chosen for root growth and gericudranin production. After 35 days culture in a half-strength liquid SH medium containing $30g^{glucose}$/l, hairy root growth reached $138g^{FW}$/I and gericudranin A and B were produced at concentrations of 27mg/l and 21 mg/l, respectively. It was also observed that the contents of gericudranin A and B in hairy root were eight and six times higher than those of cudraniae radix, respectively.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.4
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• pp.232-242
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• 2006

Bioactive compounds produced by microorganisms have focused on in recent years. In particular, novel compounds showing anti-cancer activity have been isolated from marine microorganisms. In this review, we will discuss on the studies of new bioactive compounds derived from marine bacteria with conjunction to anti-cancer activity. This review will provide an information and source for bioactive compounds showing anti-cancer activity, which were derived from marine bacteria.

• Journal of Microbiology and Biotechnology
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• v.17 no.12
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• pp.1930-1936
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• 2007

A sequential optimization strategy based on statistical experimental designs was employed to enhance the production of cyclosporin A (CyA) by Tolypocladium inflatum DSMZ 915 in a submerged culture. A 2-level Plackett-Burman design was used to screen the bioprocess parameters significantly influencing CyA production. Among the 11 variables tested, sucrose, ammonium sulfate, and soluble starch were selected, owing to their significant positive effect on CyA production. A response surface methodology (RSM) involving a 3-level Box-Behnken design was adopted to acquire the best process conditions. Thus, a polynomial model was created to correlate the relationship between the three variables and the CyA yield, and the optimal combination of the major media constituents for cyclosporin A production, evaluated using the nonlinear optimization algorithm of EXCEL-Solver, was as follows (g/l): sucrose, 20; starch, 20; and ammonium sulfate, 10. The predicted optimum CyA yield was 113 mg/l, which was 2-fold the amount obtained with the basal medium. Experimental verification of the predicted model resulted in a CyA yield of 110 mg/l, representing 97% of the theoretically calculated yield.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.4
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• pp.301-305
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• 2001

The co-expression of the arg U gene in a double-vector expression system of recombi-nant Escherichia coli BL22(DE3)[pET-IEN2a+pAC-argU] significantly enhanced the production level of reconminant human interferon -$\alpha$2a(rhIFN-$\alpha$2a) in high cell density cultures, compared to a recombinant E. coli culture containing only the single expression vector, pET-IEN2a. The dry cell mass concentration increased to almost 100 g/L, and more than 4 g/L of rhIFN-$\alpha$2a was accumu-lated in the culture broth. Evidently, the synthesis of rhIFN-$\alpha$2a was strongly dependent on the pre-induction growtih rate and more efficient at a higher specific growth rate. The additional sup-ply of tRN $A^{Arg(AGG/AGA)}$ enhanced the expression level of the rhIFN-$\alpha$2a gene in the early stage of the post-induction phase, yet thereafter the specific production rate of rhIFN-$\alpha$2a rapidly de-creased due to severe segregational instability of plasmid vector pET-IEN2a. It would appear that the plasmid instability with only occurred to pET-IEN2a in the double vector system, was re-lated to the effect of translational stress due to the over expression of rhIFN-$\alpha$2a.

• Journal of Microbiology and Biotechnology
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• v.8 no.2
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• pp.178-181
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• 1998

An exopolysaccharide, designated as A49-Pol, was produced from Bacillus polymyxa KCTC 8648P in nitrogen sufficient conditions. The viscosity of the culture broth increased up to $2\times10^4$cP in 38 hours of culture and then decreased to $1.5\times10^4$CP at 48 hours. The $1.0\%$ (w/v) solution of purified A49-Pol represented pseudoplasticity with a viscosity of $2.7\times10^4$cP which was two times higher than xanthan at the same concentration. The viscosity of the A49-Pol solution was also greatly affected by its concentration in comparison with the xanthan solution. The viscosity of $1.0\%$ A49-Pol solution was 930-fold higher than its $0.2\%$ solution, whereas the corresponding viscosities of xanthan solution experienced only l7-fold difference. The viscosity was observed to be maximum at pH 7.0 in both A49-Pol and xanthan solutions, and gradually decreased as the pHs of the polysaccharide solutions went to acidic or alkaline regions. The viscosity of A49-Pol solution was very sensitive to temperature compared to xanthan and decreased with increasing temperature. The viscosity of $0.6\%$ solution of A49-Pol was 8,100 cP at $10^{\circ}C$ and 55 cP at $50^{\circ}C$. The viscosity was also affected by the presence of surfactants such as Span 20 and Triton X-l00 ; with $0.5\%$ Triton X-l00 (v/v), the viscosity of A49-Pol solution increased by $50\%$.

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.128-134
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• 2008

The kinetics of cell growth and Cyclosporin A (Cyc A) production by Tolypocladium inflatum were studied in shake flasks and bioreactors under controlled and uncontrolled pH conditions. In the case of the shake flask, the production time was extended to 226 h and the maximal antibiotic concentration was 76 mg/l. When scaling up the cultivation process to a bioreactor level, the production time was reduced to only 70h with a significant increase in both the cell growth and the antibiotic production. The maximal dry cell weights in the case of the controlled pH and uncontrolled pH cultures in the bioreactor were 22.4g/l and 14.2g/l, respectively. The corresponding maximal dry cell weight values did not exceed 7.25g/l with the shake flask cultures. The maximal values for Cyc A production were 144.72 and 131.4 mg/l for the controlled and uncontrolled pH cultures, respectively. It is also worth noting that a significant reduction was observed in both the dry cell mass and the antibiotic concentration after the Cyc A production phase, whereas the highest rate of antibiotic degradation was observed in the stirred tank bioreactor with an uncontrolled pH. Morphological characterization of the micromorphological cell growth (mycelial/pellet forms) was also performed during cultivation in the bioreactor.

• Environmental Analysis Health and Toxicology
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• v.26
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• pp.3.1-3.6
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• 2011

Objectives: Titanium dioxide ($TiO_2$), a common nanoparticle widely used in industrial production, is one of nano-sized materials. The purpose of this study was to determine the acute and chronic toxicity of $TiO_2$ using different size and various concentrations on Daphnia magna. Methods: In the acute toxicity test, four concentrations (0, 0.5, 4, and 8 mM) for $TiO_2$ with 250 or 500 nm and five concentrations (0, 0.25, 0.5, 0.75, and 1 mM) for $TiO_2$ with 21 nm were selected to analyze the toxic effect to three groups of ten daphnia neonates over 96 hours. In addition, to better understand their toxicity, chronic toxicity was examined over 21 days using 0, 1, and 10 mM for each type of $TiO_2$. Results: Our results showed that all organisms died before the reproduction time at a concentration of 10 mM of $TiO_2$. In addition, the exposure of anatase (21 nm) particles were more toxic to D. magna, comparing with that of anatase (250 nm) and rutile (500 nm) particles. Conclusions: This study indicated that $TiO_2$ had adverse impacts on the survival, growth and reproduction of D. magna after the 21days exposure. In addition, the number of test organisms that were able to reproduce neonates gradually were reduced as the size of $TiO_2$ tested was decreased.

• Archives of Pharmacal Research
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• v.18 no.2
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• pp.84-89
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• 1995

The complexation and physical characteristics of egg phosphatidylcholine (PC) liposome containing amphotericin B(AmB) were investigated through circular dichrosim(CD) spectra, the size distribution, the turbidity change, and the calcein release. CD spectra of AmB-containing egg PC mxture exhibited a positive peak around 330 nm indicative of complexation of AmB and four negative peaks. The positive peak increased up to $2.2{\;}millidegree/{\mu}g$ AmB as AmB contents increased up to 12% (w/w), suggesting that AmB-phospholipid complexation was promoted by the antibiotics. The effective diameter of liposomesa by dynamic light scattering decreased from 450 nm to 220 nm as the amount of AmB in liposomes increased from o to 30% (w/w). The complexation may be responsible for the reduction in size. On the other hand, at around 1 mN deoxycholate (DOC), the reltive turbidities of 5 and 10% (w/w) AmB-containing liposome suspension were less than 1 probably due to the soblubilization of the complex, while those of pure PC liposome suspension were larger than 1 at the same concentration. Deoxycholate-induced release of liposomes, indicating the intercalation of the drug into the bilayers. Therefore, it is concluded that in AmB/eggPC/water system, AmB-phospholipid complexcoexists with AmB-containing liposomes.

• Journal of Animal Science and Technology
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• v.66 no.1
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• pp.178-203
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• 2024

Constipation, which refers to difficulties in defecation and infrequent bowel movement in emptying the gastrointestinal system that ultimately produces hardened fecal matters, is a health concern in livestock and aging animals. The present study aimed to evaluate the potential effects of dairy-isolated lactic acid bacteria (LAB) strains to alleviate constipation as an alternative therapeutic intervention for constipation treatment in the aging model. Rats were aged via daily subcutaneous injection of D-galactose (600 mg/body weight [kg]), prior to induction of constipation via oral administration of loperamide hydrochloride (5 mg/body weight [kg]). LAB strains (L. fermentum USM 4189 or L. plantarum USM 4187) were administered daily via oral gavage (1 × 10 Log CFU/day) while the control group received sterile saline. Aged rats as shown with shorter telomere lengths exhibited increased fecal bulk and soften fecal upon administration of LAB strains amid constipation as observed using the Bristol Stool Chart, accompanied by a higher fecal moisture content as compared to the control (p < 0.05). Fecal water-soluble metabolite profiles showed a reduced concentration of threonine upon administration of LAB strains compared to the control (p < 0.05). Histopathological analysis also showed that the administration of LAB strains contributed to a higher colonic goblet cell count as compared to the control (p < 0.05). The present study illustrates the potential of dairy-sourced LAB strains as probiotics to ameliorate the adverse effect of constipation amid aging, and as a potential dietary intervention strategy for dairy foods including yogurt and cheese.