• Journal of Microbiology and Biotechnology
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• v.21 no.12
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• pp.1250-1256
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• 2011

In this study, Bacillus licheniformis cells were immobilized by entrapment in calcium alginate beads and were used for production of alkaline protease by repeated batch process. In order to increase the stability of the beads, the immobilization procedure was optimized by statistical full factorial method, by which three factors including alginate type, calcium chloride concentration, and agitation speed were studied. Optimization of the enzyme production medium, by the Taguchi method, was also studied. The obtained results showed that optimization of the cell immobilization procedure and medium constituents significantly enhanced the production of alkaline protease. In comparison with the free-cell culture in pre-optimized medium, about 7.3-fold higher productivity was resulted after optimization of the overall procedure. Repeated batch mode of operation, using optimized conditions, resulted in continuous production of the alkaline protease for 13 batches in 19 days.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.320-325
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• 1997

Transglucosidase (TG) from Aspergillus niger was immobilized on various carriers by several immobilization methods such as ionic binding, adsorption, entrapment, covalent linkage and metal chelation to improve the process performance. The covalent linkage with CNBr-activated sepharose 4B was found as the best method for immobilization of TG based on the immobilization yield which was 61.3%. The immobilization through ionic binding and adsorption gave 33.1% and 22.5% yield respectively but both methods were not selected due to lower yield than covalent linkage using CNBr-Sepharose 4B. Internal diffusion resistance in beads developed by entrapment were not suitable factor in producing final target products. Covalent linkage of TG on magnesium silicate, silica gel and glass bead and metal chelation method didn't result in higher yield than the selected one, either.

• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.650-654
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• 2007

In our previous work, a method of pretreating lipase was developed to prevent loss of its activity during covalent immobilization. In this study, Rhizopus oryzae lipase was pretreated before immobilization and then immobilized on a silica gel surface. The effects of the various materials and conditions used in the pretreatment stage on the activity of immobilized lipase were investigated. Immobilized lipase pretreated with 0.1% of soybean oil had better activity than those pretreated with other materials. The optimal temperature, agitation speed, and pretreating time for lipase pretreatment were determined to be $40^{\circ}C$, 200rpm, and 45min, respectively. The activity of immobilized soybean oil pretreated lipase was 630U/g matrix, which is 20 times higher than that of immobilized non-pretreated lipase. In addition, immobilized lipase activity was maintained at levels exceeding 90% of its original activity after 10 reuses.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.263-265
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• 2002

We have used the secondary-step immobilization methods based on the chip pattern of hydrophobic self-assembly layers to assemble microfabricated particles onto the chip pattern. Immobilization of DNA, fabrication of the particles and the chip pattern, arrangement of the particles on the chip pattern, and recognition of each using DNA fluorescence measurement were carried out. Establishing the walls, the arrangement stability of the particles was improved. Each DNA is able to distinguish by using the lithography process on the particles. Advantages of this method are process simplicity, wide applicability and stability. It is thought that this method can be applicable as a new fabrication technology to develop a minute integration type biosensor microarray.

• Journal of the Korean Electrochemical Society
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• v.13 no.1
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• pp.70-74
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• 2010

The immobilization of proteins on silicon surfaces using electrochemical reaction has been studied. Chemical deposition of nitrobenzendiazonium (NiBD) cations is employed to modify silicon surfaces. Electrochemical reduction of nitro-group to primary amine-group have been conducted on the modified surfaces to activate silicon surfaces for the protein immobilization. Attachment of gold nanoparticles was used to prove the reduction. The current method was applied to selective activation of a silicon nanowire and immobilize proteins on the selected nanowire. It has been demonstrated that the use of chemical and electrochemical reaction NiBD is efficient for the selective immobilization of proteins on silicon nanowire surfaces.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.100-102
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• 2002

The demand for a better immobilization device has been increased in the radiation oncology field. Especially, it is essential to have a reliable and practical immobilization tool for the whole body radiosurgery and the IMRT (intensity modulated radiation therapy). A useful method to immobilize the abdomen for the external beam radiation treatment is developed. The air-injected balloon blanket (AIBB) was designed as an immobilization device. As the air was injected into it, it pressed down the patient's abdomen and fixed the patient. The AIBB played a role not only to grab the patients' motion, but also to increase the patients' setup reproducibility. Patients' movements due to the respiration were reduced and the reconstruction could be maximized. The experimental results revealed that the AIBB could be used for the clinic.

• Progress in Medical Physics
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• v.13 no.3
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• pp.176-180
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• 2002

The demand for a better immobilization device has been increased in the radiation oncology field. Especially, it is essential to have a reliable and practical immobilization tool for the whole body radio-surgery and the IMRT(intensity modulated radiation therapy). A new method to immobilize the abdomen for the external beam radiation treatment was developed. The air-injected balloon blanket (AIBB) was designed as an immobilization device. As the air was injected into the AIBB, it pressed down the patient's abdomen and fixed the patient. The AIBB played a useful role to grab the patients' motion. Displacement of the abdomen in the anterior-posterior direction, which showed moving most during the respiration, reduced by more than 5 mm. Patients' movements from the breathing were reduced. The experimental results revealed that the AIBB could be used for the clinic.

• Macromolecular Research
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• v.10 no.5
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• pp.291-295
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• 2002

Atomic force microscopy(AFM) was used to study the polyethylene(PE) surfaces grafted and immobilized with acrylic acid by Ar plasma treatment. The topographical images and parameters including RMS roughness and Rp-v value provided an appropriate means to characterize the surfaces. The plasma grafting and immobilization method were a useful tool for the preparation of surfaces with carboxyl group. However, the plasma immobilization method turned out to have a limitation to use as a means of preparation of PE surface with specific functionalities, due to ablation effect during the Ar plasma treatment process.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.199-203
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• 2001

A simple quantitative method to measure the degree of silanization was developed, based on the reaction of ninhydrin with the silanization reagent (3-aminopropyltriethoxysilane, 3-APTES). At low concentrations (0.001-0.005%, v/v) of 3-APTES, a good linearity was obtained when 3-APTES reacted with undiluted ninhydrin for 30 min. On the other hand, at high levels of 3-APTES, a linearity was obtained when 3-APTES reacted with 3-fold diluted ninhydrin for 20 min. The reliability of regression curves mentioned above was expressed as a regression coefficient ($R^2$) of more than 0.99. Immobilization of different enzymes was introduced via silanization by using the 3-APTES in order to confirm the validity of the ninhydrin method. When yield for each step in the immobilizatio process were compared, yields of both glutaraldehyde and protein were founc to have the same tendency to silanization. These results shw that the ninhydrin method was suitable for quatitative analysis of silanization and that yields of immobilization could be pre-estimated by measuring silanization levels using the ninhydrin method.

• Journal of Soil and Groundwater Environment
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• v.10 no.2
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• pp.1-11
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• 2005

This study applied EK method to remediate contaminated soil by lead (Pb), tried increasing efficiency of remediation using adsorbent (apatite and zeolite) as enhanced EK remediation method to overcome the limit of traditional EK remediation method. Adsorption tests on Pb were practiced to extract EK, making different concentration of contaminated soil, voltage condition, operating time etc., transferring Pb-ion into the position of adsorbent, then tried immobilization. On this results, the efficiency of remediation is different on its test conditions. In addition, the efficiency of remediation was not only improved by adding electrode revεrsal and install position of adsorbent but also satisfied TCLP regulation of EPA in USA through the whole sample range. Finally, absorption and immobilization capacity of apatite and zeolite proved on its excellence and confirmed the possibility of application of apatite and zeolite as enhanced EK remediation method.