• Microbiology and Biotechnology Letters
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• v.22 no.4
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• pp.407-414
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• 1994

Anaerobic fermentative bacteria were isolated from the acidogenic reactor of a labora- tory scale 2-stage anaerobic digestor. The isolate 1-6 was selected for its ablity to produce more fatty acids from distillery wastewater than others, and was identified as a strain of Clostridium. The isolate Clostridium sp. 1-6 is a thermophilic bacterium growing at 55$\circ$c , and grew best at pH 5.5. An acidogenic reactor using immobilized cells of the isolate Clostridium sp. 1-6 removed about 15% of COD from distillery wastwater as hydrogen, producing about 50 mM butyrate and about 10 mM acetate, when the reactor was operated at the hydraulic retention time(HRT) of 0.8 hr. It is proposed that this system can be used to convert the distillery wastewater to hydrogen and butyrate. More than 90% of COD was removed from the wastewater by anaerobic digestion using a 2-stage digestor consisting of a UASB methanogenic reactor and an acidogenic reactor of the immobilized cells of isolate Clostridium sp. 1-6.

• Journal of Sensor Science and Technology
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• v.26 no.6
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• pp.414-419
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• 2017

The optical characteristics of cresol red, phenol red, and neutral red immobilized in the thin film were investigated with absorbance measurement in order to find a sensing part of a fiber-optic pH sensor. Sol-Gel method with tetramethyl orthosilicate as a precursor was used to immobilize the pH indicators in the thin film. The absorbance spectra were measured when pH indicators were immobilized in the film and were dissolved in the buffer solution. Experimental results showed that the absorbance spectra could be changed when the pH indicator is immobilized in the thin film. As compared with other pH indicators, the neutral red exhibited similar absorbance spectra regardless of physical conditions and was sensitive over whole pH range between 4 and 11. In addition, the absorbance ratio of base peak to acid peak tended to increase in proportion to the increase in pH. Experimental results indicate that the neutral red is a good pH indicator for fabrication of a sensing part of the fiber-optic pH sensor.

• Membrane and Water Treatment
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• v.8 no.6
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• pp.575-590
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• 2017

PolyHIPEs membrane prepared with styrene (St), divinylbenzene (DVB), and ethylhexyl acrylate (EHA) can yield a unique pore structure provided by large voids highly interconnected by many small window throats. With the advantageous pore structure, PolyHIPE presents a potential as a support for carrier facilitated transport membrane. Tricaprylmethylammonium chloride (Aliquat 336) can be efficiently incorporated into the PolyHIPE membrane by a two-step solvent-nonsolvent method to obtain an Aliquat 336-immobilized PolyHIPE membrane with good stability. The study of Cr (VI) transport through Aliquat 336-immobilized PolyHIPE membrane indicates that the membrane has high initial flux and maxima stripping flux ($J_f^o=15.01({\mu}mol/m^2s)$, $J_s^{max}=6.15({\mu}mol/m^2s)$). The reusability study shows that the Aliquat 336-immobilized PolyHIPE membrane can maintain high Cr(VI) recovery efficiency even after 15 cycles of operations. The developed membrane was also used in the separation of Cr (VI) from other anions (i.e., $SO_4{^{2-}}$ and $NO_3{^-}$) and other cations (i.e., Ni (II), Mg (II) and Cu (II)) with good selectivity.

• Biotechnology and Bioprocess Engineering:BBE
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• v.2 no.2
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• pp.77-81
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• 1997

Removal of nitrogen compound from waste water is essential and often accomplished by biological process. To prevent washout and to develop an efficient bioreactor, immobilization of sutibal microorganisms could be sensible approach. Strains and permeabilized cell encapsulated in cellulose nitrate microcapsules and immobilized on polystyrene films were prepared by the method described in the previous study. In the wastewater treatment system, nitrification of ammonia component is generally known as rate controlling step. To enhance the rate of nitrification, firstly nitrifying strains Nitrosomonas europaea(IFO14298), are permeabilized chemically, and immobilized on polystyrene films and secondly oxidation rates of strain system and permeabilized strain system are compared in the same condition. with 30 minute permeabilized cells, it took about 25 hours to oxidize 70% of ammonia in the solution, while it took about 40 hours to treat same amount of ammonia with untreated cells. All the immobilization procedures did not harm to the enzyme activity and no mass transfer resistance through the capsule well was shown. In the durability test of immobilized system, the system showed considerable activity for the repeated operation for 90 days. With these results, the system developed in this study showed the possibility to be used in the actual waste water treatment system.

• KSBB Journal
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• v.29 no.4
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• pp.239-243
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• 2014

Recently, there is a growing interest in efficient biomass pretreatment and saccharification processes to produce biofuels and biochemicals from renewable non-food biomass resources. In this study, glucose was produced from cellulose by immobilizing cellulase enzyme on chitosan beads which was reported to have high pH and temperature stability. The immobilized amounts of cellulase on chitosan beads linearly increased with increasing the concentrations of cellulase solution. The glucose production increased to 7.2 g/L from 1% carboxymethyl cellulose (CMC) substrate when immobilized at 20% cellulase solution. The maximum specific activity was 0.37 unit/mg protein when immobilized at 8% cellulase solution. At pH 7 and $37^{\circ}C$, the optimum reaction composition was 0.5 g beads/L from 1% CMC substrate. At this condition, the conversion to glucose completed at ca. 20 min.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.227-228
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• 1998

Lumbrokinase, potent fibrinolytic enzyme purified from earthworm, was immobilized onto polyurethane valves using photoreaction, photoreactive polyallyl-amino as a photoreactive linker. For evaluation of blood compatibility, lumbrokinase immobilized polymer valves were assembled into the total artificial heart (TAH). This TAH was implanted to 60kg healthy lamb for 1-3 days with the cardiac output 5 L/min. In the control lamb, the valves were untreated, in ore other, only valves on the right were treated, and in the remaining animal, only those on the left. To facilitate the thrombus formation, low doses of heparin were administered. For evaluation of the immobilized lumbrokinase, thrombus formation, proteolytic and fibrinolytic activity was measured. This data shows that lumbrokinase-treated polyurethane valves lead to decreased thrombus formation in vivo, and that their biocompatibility is therefore higher than that of untreated valves.

• The Korean Journal of Food And Nutrition
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• v.6 no.3
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• pp.158-168
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• 1993

For the conversion of WAD to NADP, Immobilized Brevibacterium ammoniagenes cells with NAD kinase was coupled with ATP-generating system by acetate kinase. The membrane permeability of B. ammoniagenes was improved by toluene treatment of cells. The toluene treated B. ammoniagenes cells were immobilized for stable enzyme activity. Partially purified acetate kinase was used in the reaction system. The optimum conditions for the efficient conversion of UAD to WADP by energy-coupled system were investigated. B. ammoniagenes cells treated with toluene for the Improvement of membrane permeability showed 4.5 fold improved permeability in the conversion of NAD to NADP compared with Intact cells. 3% k-carrageenan as the immobilization matrix of B. ammoniagenes showed the best efficiency for the conversion of NAD to NADP The optimum conditions for the WAR to WARP conversion reaction coupled nth ATP-generating system were 10mM acetylphosphate, 5mM ADP 200mM inorganic phosphate, 10mM MgCl2, 250mg/ml Immobilized cells, 49.3mUnit/ml acetate kinase, pH 7.5 and 37$^{\circ}C$. Under the optimum conditions, 72% of 5mM(340mg/ml ) NAD was converted to UADP In 12 hours.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.2
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• pp.89-94
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• 2002

The continuous production of citric acid from dairy wastewater was investigated using calcium-alginate immobilized Asrergillus niger ATCC 9142. The citric acid productivity and yield were strongly affected by the culture conditions. The optimal pH, temperature, and dilution rate were 3.0, 30$^{\circ}C$, and 0.025 h$\^$-1/, respectively. Under optimal culture conditions, the maximum productivity, concentration, and yield of citric acid produced by the calcium-alginate immobilized Aspergillus niger were 160 mg L$\^$-1/ h$\^$-1/, 4.5 g/L, and 70.3%, respectively, The culture was continuously perfored for 20 days without any apparent loss in citric acid productivity. Conversely, under the same conditions with a batch shake-flask culture, the maximum productivity, citric acid concentration, and yield were only 63.3 mg L$\^$-1/h$\^$-1/, 4.7 g/L and 51.4%, respectively, Therefore, the results suggest that the bioreactor used in this study could be potentially used for continuous citric acid production from dairy wastewater by applying calcium-alginate immobilized Aspergillus niger.

• Polymer(Korea)
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• v.28 no.6
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• pp.538-544
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• 2004

Polyurethanes containing L-lysine segments in the main chain (PULL) were synthesized from 4,4'-diphenymethyl diisocynate, poly(tetramethylene glycol), and z-lysine oligomer as a chain extender. Insulin-immobilized polyurethanes (PULL-In) were prepared by a coupling reaction of PULL surface amino groups with insulins. The amount of immobilized insulin was about 0.30 nmol/$\textrm{cm}^2$, as determined by Bradford method. The interactions of NIH/3T3 fibroblasts with surface-modified PULLs were investigated using $^3$H-thymidine incoporation and optical microscopy. The cell growth rate on PULL-In film was higher than those on other substrates. The cell proliferation by the immobilized insulin was almost same as that by the free one.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.5
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• pp.741-750
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• 2011

A pilot-scale biofilter was constructed to discover degradation characteristics of the complex odor discharged from Ansan wastewater treatment plant. Candida tropicalis for volatile organic compounds, sulfur oxidizing bacteria(SOB) for hydrogen sulfide, and bacteria extracted from feces soil were immobilized on a polymer gel media. According to this study, the EBCT was varied from 36 sec to 18 sec. Toluene was removed as 80% along the variations, but it was recovered as 100% within 1 week. All benzene and xylene were removed during the operation while the efficiency of hydrogen sulfur was temporary decreased at 18 sec of EBCT, thereafter it was recovered to 100% within a week. The maximum elimination capacities of the benzene, toluene, xylene, and hydrogen sulfur were 6.6 g/$m^{3}$/hr, 31.7 g/$m^{3}$/hr, 7.8 g/$m^{3}$/hr, and 133.6 g/$m^{3}$/hr, respectively. There were merits on removal both organic and inorganic complex odor using the pilot-scale biofilter embedded with microorganisms immobilized on polymer gel media.