• Proceedings of the Membrane Society of Korea Conference
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• 1999.07a
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• pp.43-47
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• 1999

Pd-ceramic composite membranes and catalytic membrane reactors(CMR) have been studied for hydrogen purification and recovery in th fusion reactor fuel cycle. The development of techniques for coating microporous ceramic tubes with Pd and Pd/Ag layers is described: composite membranes have been produced by electroless deposition (Pd/Ag film of 10-20${\mu}{\textrm}{m}$) and rolling of thin metal sheet (Pd and Pd/ Ag membranes of 50-70 ${\mu}{\textrm}{m}$). Experimental results on electroless membranes showed that the metallic film presented some defects and the membranes had not complete hydrogen selectivity . Then the catalytic membrane reactors with electroless membranes can be applied for some industrial processes that do not require a complete separation of the hydrogen (i.e. in the dehydrogenation of hydrocarbons). The rolled thin Pd/Ag membranes separated the hydrogen from the other gas with a complete selectivity and exhibited a slightly larger (about a factor 1.7) mass transfer resistance with respect to the electroless membranes. Experimental tests confirmed the good performances in terms of durability.

• Microbiology and Biotechnology Letters
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• v.22 no.3
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• pp.271-276
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• 1994

The strain S4-14 which produced alkaline lipase and had resistance against linear alkylbenzene sulfonate was isolated from soil or water samples. The isolated strain S4-14 was identified a species belong to Pseudomonas. Alkalin lipase secreted by Pseudomonas sp. S4-14 was purified by ammonium sulfate precipitation procedure follwed by DEAE-Cellulose, DEAE-Sepharose and gel filtration chromatohraphies with 995.15 U/mg protein and 16.1% yield. The molecular weight of the enzyme was estimated to be 65,000 dalton by SDS-PAGE. The optimum pH and temperature of the purified enzyme was 10.5 and 45$\circ $C, respectively. The emzyme was stable at 45$\circ $C for 1 hr and in a pH range from 8.0 to 12.0 for 24 hr at 4$\circ $C. The activity of lipase was enhanced by Ca$^{2+}$ while inhibited strongly by Pb$^{2+}$, Zn$^{2+}$ or Fe$^{3+}$. The activity of lipase was inactivated about 50~60% in the presence of 50 mg/l linear alkylbenzene sulfonate, $\alpha $-olefin sulfonate, alcohol ethoxylate or perborate.

• Journal of Microbiology and Biotechnology
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• v.21 no.8
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• pp.808-817
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• 2011

Because of its elevated cellulolytic activity, the filamentous fungus Trichoderma harzianum has a considerable potential in biomass hydrolysis applications. Trichoderma harzianum cellobiohydrolase I (ThCBHI), an exoglucanase, is an important enzyme in the process of cellulose degradation. Here, we report an easy single-step ion-exchange chromatographic method for purification of ThCBHI and its initial biophysical and biochemical characterization. The ThCBHI produced by induction with microcrystalline cellulose under submerged fermentation was purified on DEAE-Sephadex A-50 media and its identity was confirmed by mass spectrometry. The ThCBHI biochemical characterization showed that the protein has a molecular mass of 66 kDa and pI of 5.23. As confirmed by smallangle X-ray scattering (SAXS), both full-length ThCBHI and its catalytic core domain (CCD) obtained by digestion with papain are monomeric in solution. Secondary structure analysis of ThCBHI by circular dichroism revealed ${\alpha}$- helices and ${\beta}$-strands contents in the 28% and 38% range, respectively. The intrinsic fluorescence emission maximum of 337 nm was accounted for as different degrees of exposure of ThCBHI tryptophan residues to water. Moreover, ThCBHI displayed maximum activity at pH 5.0 and temperature of $50^{\circ}C$ with specific activities against Avicel and p-nitrophenyl-${\beta}$-D-cellobioside of 1.25 U/mg and 1.53 U/mg, respectively.

• Applied Biological Chemistry
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• v.12
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• pp.99-105
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• 1969

The yield of cellulase derived from Trichoderma $(O_2-1)$ was remarkably varied with various concentration of ethanol and acetone in purification of the enzyme. In the purification with ethanol of ${\beta}-glucosidase$, the best result was obtained in the concentration of 60% and, of CMCase and of filter paper disintegrating enzyme 80%. And in the purification with acetone of ${\beta}-glucosidase$, filter paper disintegrating enzyme, and CMCase, in the concentration of 60%, 80%, and 90% respectively, was shown the best yield. The activities of crude Cellulase preparation could be seperated into few of fractions by column chromatography with Silica gel, Cellulose powder, and gauze. Most of CMCase, avicelase, and ${\beta}-glucosidase$ were eluted, but most of filter paper disintegrating enzyme and the rest of enzymes mentioned the above were absorbed, and were eluted with water. Therefore, it was considered that CMCase is different from filter paper disintegrating enzyme in properties. The relative activity of CMCase was different from that of avicelase in the peak of elusion part. And it was considered that filter paper disintegrating enzyme and cellulose powder saccharifying enzyme was seperated respectively as absorption part and non absorption part. The auther came to the conclusion that at least there were more than three sorts of cellulase in Trichoderma $(O_2-1)$ cellulase preparation.

• Carbon letters
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• v.26
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• pp.31-42
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• 2018

Adsorption is one of the best methods for wastewater purification. The fact that water quality is continuously decreasing requires the development of novel, effective and cost available adsorbents. Herein, a simple procedure for the preparation of a magnetic adsorbent from agricultural waste biomass and ferrofluid has been introduced. Specifically, ferrofluid mixed with wheat straw was directly pyrolyzed either by microwave irradiation (900 W, 30 min) or by conventional heating ($550^{\circ}C$, 90 min). Magnetic biochars were characterized by X-ray powder diffraction, $M{\ddot{o}}ssbauer$ spectroscopy, textural analysis and tested as adsorbents of As(V) oxyanion and cationic methylene blue, respectively. Results showed that microwave pyrolysis produced char with high adsorption capacity of As(V) ($Q_m=25.6mg\;g^{-1}$ at pH 4), whereas conventional pyrolysis was not so effective. In comparison to conventional pyrolysis, one-step microwave pyrolysis produced a material with expressive microporosity, having a nine times higher value of specific surface area as well as total pore volume. We assumed that sorption properties are also caused by several iron-bearing composites identified by $M{\ddot{o}}ssbauer$ spectroscopy ([super] paramagnetic $Fe_2O_3$, ${\alpha}-Fe$, non-stoichiometric $Fe_3C$, ${\gamma}-Fe_2O_3$, ${\gamma}-Fe$) transformed from nano-maghemite presented in the ferrofluid. Methylene blue was also more easily removed by magnetic biochar prepared by microwaves ($Q_m=144.9mg\;g^{-1}$ at pH 10.9) compared to using conventional techniques.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2005.06a
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• pp.245-247
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• 2005

A cellulolytic fungus isolated from Agave plantation in northeastern Thailand was identified as Acrophialophora nainiana. The fungus was capable of growing at pH between 3 - 7 and 25 - 45 $^{\circ}C$, with the optimum conditions at pH 5.0 and 40 $^{\circ}C$. The wild isolate produced cellulases, comprising of exoglucanase (0.019 U/mg protein), endoglucanase (0.366 U/mg protein), and ${\beta}$-glucosidase (0.001 U/mg protein). Mutations with UV and NTG produced the UV 10-2 mutant with cellulases activities including exoglucanase (0.093 U/mg protein), endoglucanase (0.585 U/mg protein), and ${\beta}$-glucosidase (0.013 U/mg protein). Purification of the enzymes with ultrafiltration, ammonium sulfate precipitation, and ion-exchange chromatography yielded the maximal cellulase specific activities of 2.736 U/mg protein (exoglucanase), 0.235 U/mg protein (endoglucanase), and 0.008 U/mg protein (${\beta}$-glucosidase). The mutant's cellulases were the most active at pH 5.0 and 60 $^{\circ}C$. Ion-exchange chromatography revealed that A. nainiana UV 10-2 cellulases were comprised of two peaks with one peak showing the single endoglucanase activity while the other peak showed a mixture of the three enzyme activities. Production of A. nainiana UV 10-2 cellulases using banana leaf stalk as the sole carbon source gave comparable yields to that of the pure ${\alpha}$-cellulose. The enzymes were used in the simultaneous saccharification and fermentation (SSF) of plant residue (Coix aquatica) along with Kluveromyces marxianus to produce ethanol. Moreover, when the enzymes were used in the bioscouring process of fabric, the desiravle traits of textile processing including immediate water absorbency, increased in whiteness and reduction of yellowness of the treated fabric were observed.

• Food Science and Biotechnology
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• v.14 no.5
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• pp.704-708
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• 2005

Poly-y-glutamate (${\gamma}$-PGA) has great potential as a biodegradable polymer in a broad range of industrial fields such as food, cosmetics, medicine and water treatment. In order to isolate ${\gamma}$-PGA producers that are suitable for specific industrial applications, 653 Bacillus-like strains were isolated from 439 varieties of three Korean fermented foods, Cheongkukjang, Doenjang, and Kochujang, which were collected from different regions across Korea. A very high level of ${\gamma}$-PGA production was demonstrated in 4.7%, 1.8%, and 3.0% of the Bacillus-like strains isolated from Cheongkukjang, Doenjang, and Kochujang samples, respectively, which produced a viscous substance to such extent that it overflowed to the lid of the plate on the glutamate-dependent ${\gamma}$-PGA production plates. On glutamate-independent ${\gamma}$-PGA production plates, 5.1%, 5.9%, and 6.1% of Bacillus-like strains isolated from Cheongkukjang, Doenjang, and Kochujang samples, respectively, showed high production. The maximum ${\gamma}$-PGA production yields were 32.5 g/L and 5 g/L, depending on the purification methods in the glutamate-dependent media, with the higher yield resulting from a simple precipitation of ${\gamma}$-PGA by either methanol or ethanol and dialysis. The viscous substance produced by each strain showed different morphological characteristics, suggesting that isolated ${\gamma}$-PGA producers could produce various types of ${\gamma}$-PGA.

• Korean Journal of Environmental Agriculture
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• v.19 no.5
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• pp.401-418
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• 2000

1. Production of the artificial zeolite from coal ash Coal fly ash is mainly composed of several oxides including $SiO_2$ and $Al_2O_3$ derived from inorganic compounds remained after burning. As minor components, $Fe_2O_3$ and oxides of Mg, Ca, P, Ti (trace) are also contained in the ash. These components are presented as glass form resulting from fusion in the process of the combustion of coal. In other word, coal ash may refer to a kind of aluminosilicate glass that is known to easily change to zeolite-like materials by hydrothermal reaction. Lots of hot seawater is disposing near thermal power plants after cooling turbine generator periodically. Using seawater in the hydrothermal reaction caused to produce low price artificial zeolite by reduction of sodium hydroxide consumption, heating energy and water cost. As coal ash were reacted hydrothermally, peaks of quartz and mullite in the ash were weakened and disappeared, and new Na-Pl peaks were appeared strengthily. Si-O-Si bonding of the bituminous coal ash was changed to Si-O-Al (and $Fe^{3+}$) bonding by the reaction. Therefore the produced Na-Pl type zeolite had high CEC of 276.7 $cmol^+{\cdot}kg^{-1}$ and well developed molecular sieve structure with low concentration of heavy metals. 2. Utilization of the artificial zeolite in agro-environment The artificial zeolite(1g) could remove 123.5 mg of zinc, 164.7 mg copper, 184.4 mg cadmium and 350.6 mg lead in the synthetic wastewater. The removability is higher 2.8 times in zinc, 3.3 times in copper, 4.7 times in cadmium and 4.8 times in lead than natural zeolite and charcoal powder. When the heavy metals were treated at the ratio of 150 $kg{\cdot}ha^{-1}$ to the rice plant, various growth inhibition were observed; brownish discoloration and death of leaf sheath, growth inhibition in culm length, number of panicles and grains, grain ripening and rice yield. But these growth inhibition was greatly alleviated by the application of artificial zeolite, therefore, rice yield increased $1.1{\sim}3.2$ times according to the metal kind. In addition, the concentration of heavy metals in the brown rice also lowered by $27{\sim}75%$. Artificial Granular Zeolites (AGZ) was developed for the purification of wastewater. Canon exchange capacity was 126.8 $cmol^+{\cdot}kg^{-1}$. AGZ had Na-Pl peaks mainly with some minor $C_3S$ peaks in X-ray diffractogram. In addition, AGZs had various pore structure that may be adhere the suspended solid and offer microbiological niche to decompose organic pollutants. AGZ could remove ammonium, orthophosphate and heavy metals simultaneously. Mixing ratio of artificial zeolite in AGZs was related positively with removal efficiency of $NH_4\;^+$ and negatively with that of $PO_4\;^{3-}$. Root growth of rice seedling was inhibited severely in the mine wastewater because of strong acidity and high concentration of heavy metals. As AGZ(1 kg) stayed in the wastewater(100L) for 4days, water quality turned into safely for agricultural usage and rice seedlings grew normally.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.2
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• pp.92-100
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• 2001

The purpose of this study is to develop a method to spread out the ecological ponds in urban areas more effectively. It is urgent to supply the ecological ponds in more broad scope to ensure the water space in urban areas which has been dried out. It is necessary to formulate a plan for improving the amenity in the cities through creation a biotop in swampy land by building rainfall ponds. Thus, a model of the ecological pond in this study has been developed by reviewing the related researches which provide the theoretical basis and by considering the characteristics of nature for a naturally approached pond. This study has produced a ecological pond model in order to introduce and spread out damp biotop. Ecological aspects have been mainly considered in designing and building the pond model. This model consists of areas for emerged plants and bog plants and has its advantage in providing animals and insects with habitats and shelters. In addition, the model includes areas for emerged plants, which are very effective in purification of the rainfall from the rooftop. After the construction of the pond, the plants were planted according to the plan, and the infiltration trench was installed beside the pond to drain out the overflow of the pond. The result of this research has shown the possibility of supplying the ecological pond in small parks and in schools of the city in an easy way. Through the application of this pond system, the water cycle and the ecosystem in urban areas will be improved.

• Microbiology and Biotechnology Letters
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• v.28 no.5
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• pp.270-278
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• 2000

The study was performed to investgate the excellent microbial anticaries substance which is more effective that the chlorhexidine in the dental caries treatment. A typi-cal strain which produced the most excellent antimicrobial subatance was selected. and identified novel alkalophillic Bacillus alkalophilshaggy JY-827. For the maximal production of themicrobial antibiotic against Streptococcus mutans from B. alkalophilshaggy JY-827, the optimal culture condition was in the medium containing glucose 15g/ L, pepton 10g/L and $K_2$$HPO_4$ 2g/L the highest production of antibiotic against S.mutans was obtained at $25^{\circ}C$ and pH 11.0 for 5 days. The antibiotic from B. alkalophilshaggy JY-827 was purified by organic solvent extraction, silica gel and sephadex LH-20 column chromatograpies, and then crystallized with methanol. The crystallin compoma-tion of this antibiotic was as a curcular shape. The melting point and rm[$\alpha$]$D^{20}$ were 152-154$^{\circ}C$ and +55。, respec-tively. Based on Instumental analyses such as FT-IR, $^{1}$H-NMR $^{13}$ C-NMR and GC-mass, the antibiotic was identified as aminoglycoside. It was obtained as amorphous white power, and soluble in water power, and soluble in water, methanol but insoluble in ether, chroloform. This antibiotic inhibited the growth of S.mutans to about 3 day at the concentration of $2.5$\times$10^{-7}$ /M. It was stable at the alkalli condition but unstable within the acid condition. It was also stable up to $70^{\circ}C$.