• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2003년도 생물공학의 동향(XII)
• /
• pp.223-227
• /
• 2003

Mevinolic acid (MA), a secondary metabolite produced by a filamentous fungus Aspergillus terreus, is acidic form of lovastatin which has been identified as a powerful cholesterol-lowering agent in humans. When immobilized cell culture was performed, MA production was about 5.3-fold higher than the parallel suspended cell culture. Although the immobilized cells proliferated slowly during exponential in comparison with the suspended cells, oxygen uptake rate and oxygen mass transfer coefficient of the immobilized cell culture were about 1.3- and 2.5- fold higher respectively than those of the parallel suspended cell culture. From these results, it was concluded that MA biosynthesis was closely dependent on the cell growth rate, morphology and oxygen availability.

• Carbon letters
• /
• 제11권3호
• /
• pp.216-223
• /
• 2010

Two-types of ionically modified multi-walled carbon nanotube (MWNTs) based sensors were developed by radiationinduced graft polymerization using vinyl monomers such as 3-(butyl imidazol)-2-(hydroxyl)propyl methyl methacrylate and 1-[(4-ethenylphenyl)methyl]-3-buthyl-imidazolium chloride with ionic properties, in aqueous solution at room temperature. Subsequently, the tyrosinase-immobilized biosensor was fabricated by a hand-casting of the ionic property-modified MWNTs, tyrosinase, and chitosan solution as a binder onto ITO glass surface. The sensing ranges of the tyrosinase-biosensor for phenol in phosphate buffer solution was in the range of 0.005~0.2 mM. The total phenolic compounds mainly such as caffeine of the tyrosinase-immobilized biosensor for commercial coffee were also determined.

• 한국미생물생명공학회:학술대회논문집
• /
• 한국미생물생명공학회 1986년도 추계학술대회
• /
• pp.523.2-523
• /
• 1986

The hydrolysis of olive oil was attempted with immobilized C. rugosa lipase in the reverse phase solvent system. (i.e. immobilized wet particles is dispersed in continuous phase olive oil or organic solvents containing olive oil). Sephadex LH-20 and LH-60 were used as the supports that can be used in organic solvents. The water content of wet particles of sephadex LH-20 and LH-60 were about 72% (w/w) and 85% (w/w), respectively Both swollen gels with 0.05M buffers adsorbed about 18% of lipase dissolved. They were easily dispersed in liquid olive oil or in organic solvents. The effects of organic solvents on the stability and catalytic activity of the lipase have been examined. The results revealed that isooctane is superior to the other solvents examined for enzymatic fat spliting in reverse phase system. Kinetics of enzymatic hydrolys of olive oil by immobilized lipase has been investigated in a batch reactor. Effects of pH and temperature on the lipase were studied. The substrate concentration was influenced positively on the thermal stability.

• Journal of Pharmaceutical Investigation
• /
• 제21권3호
• /
• pp.143-147
• /
• 1991

${\alpha}-amylase$ was immobilized on the surface of polyethylene glycol(M.W. 2000) grafted polyurethane film using diisocyanate in an attemp to develop enzyme immobilized polymeric materials. The surface morphology of the modified polyurethane film was examined by SEM. Effects of pH and temperature on the activity of the immobilized ${\alpha}-amylase$ were investigated. The optimal pH range of the activity was $7.0{\sim}7.5.$ The immobilized ${\alpha}-amylase$ demonstrated high thermal stability and maintained consistent activity during long-term storage.

• 한국식품영양학회지
• /
• 제11권3호
• /
• pp.319-322
• /
• 1998

본 실험에서는 GI 활성이 높은 alkalophilic Streptomyces sp.를 사용하여 2% $ extsc{k}$-carrageenan에 균체를 고정화 균체의 효소학적 특성을 살펴보았다. pH stability는 pH가 7.5~8.5에서 GI 활성이 가장 높았으며, reaction temperature는 7$0^{\circ}C$, Co2+는 10-3M, Mg2+는 10-3M일 때 GI 활성이 가장 높은 것으로 나타났다.

• 한국미생물·생명공학회지
• /
• 제27권6호
• /
• pp.484-490
• /
• 1999

Various materials including sodium alginate, k-carrageenan, collagen and polyacrylamide were studied in order to maintain the stability of bioluminescence of Photobacterium for the monitoring of volatile toxic substances. Kinetic parameters of specific rate($\mu$), and gamma(${\gamma}$) value were determined for the relationship between bioluminescence of immobilized P. phosphoreum and toxic substances. The bioluminescence intensity was found to be proportional to the concentration of toxic substances and the free cells were shown to be more sensitive than immobilized cells when volatile substances were exposed to the cells. Bioluminescence increased slightly after several minutes, which was due to the volatility of toxic compounds. Furthermore, P. phosphoreum immobilized on strontium alginate was better than cells immobilized on sodium alginate for the response to substances used.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1997년도 춘계학술대회
• /
• pp.16-18
• /
• 1997

The adhesion of stimulated and unstimulated platelet to fibrinogen requires the receptor binding site of GPIIb/IIIa. These recognition sites are existed in the Au chain(RGDS at positions 572-575 and RGDF at 95-98) and the carboxyterminal $\gamma$ chain (HHLGGAKQAGDV at 400-411) of fibrinogen. The unstimulated platelet does not adhered on the fragment E-coated surface containing RGDF sequence. In this study, we developed RGDF-immobilized surface to detect the functional state of platelet. RGDF-immobilized surface was prepared on the glass using photolithographic technology. Platelet adhesion to petide(RGDF)-immobilized surface was observed by the fluorescence microscope using mepacrine.

• 한국고분자학회:학술대회논문집
• /
• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
• /
• pp.267-267
• /
• 2006

Human umbilical cord blood was stored at $4^{\circ}C$ in the Pluronic-immobilized flask as well as commercially available bio-inert flasks, and flow cytometric analysis of surface markers was performed on hematopoietic stem cells after cultivation. The number of cells expressing $CD34^{+}$ in umbilical cord blood on the Pluronic-immobilized flask was extremely higher than those obtained using other flasks. It is concluded that the flexible and hydrophilic segments of Pluronic conjugated on the flask surface are the reason for the effective preservation of hematopoietic stem cells in the Pluronic-immobilized flask.

• 한국환경보건학회지
• /
• 제28권3호
• /
• pp.55-63
• /
• 2002

This study was carried out to treat textile wastewater using anaerobic sludge and aerobic fixed-bed biofilm reactor immobilized with Bacillus sp. dominated activated sludge(Bacillus sp. fraction : 81.5%). The range of influent con-centration of SCOD and soluble color were 1032-1507 mg/1, and 1239-1854 degree, respectively. Continuous treatment experiments were performed with variation of textile wastewater ratio at a same HRT. When textile wastewater ratio was 100%(HRT : 24 hours), The removal efficiency of SCOD and soluble color were 88% and 78%, respectively. When compare aerobic reactor of this study that was immobilized with Bacillus sp. dominated activated sludge to other study that was immobilized with activated sludge, SCOD and soluble color removal efficiency of this study showed a little higher efficiency than immobilized with activated sludge. The Bacillus sp. fraction of initial condition was 81.5%), but the fraction after operation was decreased to 31.8%).

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제7권6호
• /
• pp.367-370
• /
• 2002

Candida cylindracea lipase was immobilized by adsorption on acid washed glass beads. It was observed that protein loading of the support depends on the size of the particle, with smaller particle containing higher amount of protein per unit weight. Initial reaction rate linearly varied up to enzyme concentration of 17.25 U/mL. Amount of free fatty acids produced was linearly proportional up to the enzyme loading of 1650 $\mu$g/g of bead. Achievement of chemical equilibrium took longer time in the case of less protein loading. Degree of hydrolysis was found to decrease in second and third consecutive batch operations on repeated use of immobilized lipase.