• Korean Journal of Microbiology
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• v.30 no.3
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• pp.160-163
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• 1992

Killer toxin from killer yeast fusant FWKS 260 developed by protoplast fusion between the wild killer yeast and alcohol-fermenting yeast was purified by ammonium sulfate fractionation. Amicon PM I0 concentration. Sephadex G-200 and Scphadcx G-75 column chromatography. The purified killer toxin showed a single band by SIX-polyacvlamide gel electrophoresis. The protein part of killer toxin was active site. which was found by treating the proteolytic enzyme such as pronase E and pepsin to killer toxin. The killer toxin was stable at pH 2.0-5.0 and 20$^{\circ}$C. but inactivated with increasing temperature. The molecular weight was determined to be approximately 13.000 according to the results obtained from the SDS-polyacrylamide gel electrophoresis. It was confirmed that the purified killer toxin is glycoprotein by showing a red single band after st'tining with Schiffs reagent.

• Korean Journal of Microbiology
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• v.28 no.2
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• pp.128-133
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• 1990

The chromatin of all higher eukaryotic cells contains a group of very basic low-mole-cular weight proteins, the histones. But much less is known about histones in lower eukaryotes. Our purpose was to study the histones of the genus Rhizopus. After isolation and purification of nucleoprotein the basic nucleoproteins were analyzed by gel electrophoresis, in sodium dodecyl sulfate as well as acid/urea gels and compared with calf thymus histones. Their electrophoretic mobility in polyacrylamide gel indicate that they are histone homologous, although not identical, to the H2A, H2B, H3 and H4 histones of mammals with the exception of H1. The result suggests that Rhizopus thus appears to contain histone proteins which are homologous to the histones from in higher eukaryotes. The similarity between the calf thymus histone H1 and the Rhizopus high band group remains to be discussed.

• Microbiology and Biotechnology Letters
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• v.19 no.1
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• pp.57-63
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• 1991

A strain J-19 was isolated from soil, produced lipase which has resistant against alkali and linear alkylbenzene sulfonate. The strain was identified as Pseudornonns sp.. The enzyme was purified by ammonium sulfate precipitation, DEAE-Sephadex and Sephadex G- 100 column chromatography. The specific activity of the purified enzyme was 35 unit/mg protein and the yield of enzyme activity was 17%. The purified enzyme showed a single band on polyacrylamide disc gel electrophoresis. Mo1ecul;tr weight of the purified enzyme was estimated about 36,000 by Sephadex GI00 gel filtration and SDS-polyacrylarnide gel electrophoresis. The optimum pH and temperature were pH 10.0 and $30^{\circ}C$, respectively. Activity of the purified enzyme was increased 2-fold by the addition of 0.1% linear alkylbenzene sulfonate and 2.5- fold by the addition of 0.05% Tide. This enzyme remained stable from pH 8.0 to 10.0 and stable up to $40^{\circ}C$.

• Korea-Australia Rheology Journal
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• v.16 no.2
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• pp.63-73
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• 2004

Flow in a channel with an obstruction at the entry can be reverse, stagnant or forward depending on the position of the obstruction. These flow phenomena have potential applications in the control of energy and various flows in process engineering. Parameters that affect this flow inside and around the test channel are the gap (g) between the obstruction geometry and the test channel, the Reynolds number (Re) and the length (L) of the test channel. The influence of these parameters on the flow behavior was investigated using a flat plate obstruction at the entry of the channel. A low concentration polyacrylamide solution (0.018% by weight) showing a powerlaw fluid behavior was used as the fluid in this investigation. The flow phenomena were investigated by the velocity measurement and the flow visualization and their results were compared with numerical simulation. These results of low concentration polyacrylamide solution are also compared with the results of water published elsewhere (Kabir et al., 2003). The maximum reverse flow inside the test channel observed was 20% - 30% of the outside test channel velocity at a g/w (gap to width) ratio of 1 for Reynolds numbers of 1000 to 3500. The influence of the test channel length (L) and the Reynolds number (Re) on the velocity ratio ($V_i$/$V_o$: inside velocity/outside velocity in the test channel) are also presented and discussed here.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.863-868
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• 2009

The drag reduction(DR) for Betaine+Amin and Xantan Gum as kinds of surfactant and Polyacrylamide as kinds of polymer solution according to the fluid velocity, temperature and surfactant concentration were compared experimentally. For this study, two kinds of experimental apparatus for short time and long time measurement were established. Each experimental appratus was equipped with hot water storage tanks, pumps, testing pipe network, flowmeter, two pressure gauges and data logging system was built for them. Results showed that Betaine+Amin and Xanthan Gum as kinds of surfactant had appeared optimal DR around 200-500 ppm and their DR tended to be decreased when flow velocity increased but Polyacrylamide as kinds of polymer solution showed the opposite trend to be increased when flow velocity increased. The both of them showed above 40% DR in the case of better condition by the short term measurement. But Polyacrylamide as kinds of polymer solution showed more degradation than Betaine+Amin and Xanthan Gum as kinds of surfactant by the long term measurement. As a result, Betaine+Amin and Xanthan Gum as kinds of surfactant showed better materials to use to the district heating system.

• Journal of the Korean Ceramic Society
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• v.41 no.3
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• pp.253-258
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• 2004

Non-aggregated nanoscale $\alpha$-Al$_2$O$_3$ powders were prepared successfully by polyacrylamine (PAA) gel method. The method was very simple and polymer network inhibited the aggregate of $\alpha$-Al$_2$O$_3$ powders. In this investigation, nanoparticles of $\alpha$-Al$_2$O$_3$ with a diameter of about 8-15 nm were fabricated by calcining the gel precusors with various concentrations of aluminum sulfate, acrylamide and N,N'-methylene-bis-acrylamide (BIS) in air at 110$0^{\circ}C$ for 2 h. The molar ratio of aluminum sulfate to acrylamide did not have any influence on the size of particles. On the other hand, as the molar ratio of BIS to acrylamide increased, the size of nanoparticles decreased.

• Microbiology and Biotechnology Letters
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• v.20 no.2
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• pp.169-177
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• 1992

An alkaline protease producing microorganism was isolated from soil and identified as Streptomyces griseus HC-1141. The optimum culture condition of Streptomyces griseus HC- 1141 for the production of alkaline protease was as follows; 0.5% casein, 0.05% ammonium chloride, 0.1% ferrous sulfate. 2.0% lactose, pH 8.0 and 84 hrs. The enzyme was purified about 53 folds by ammonium sulfate treatment, DEAE-cellulose ion exchange chromatography and gel filtratioo on Sephadex G-150. The homogeneity of the purified enzyme was verified by polyacrylamide gel electrophoresis. The molecular weight was estimated to be 31,000 on sodium dodecyl sulfate polyacrylamide gel electrophoresis. This enzyme consists of glycine and glutamic acid as major amino acids. The N-terminal and C-terminal residues of the alkaline protease were leucine and histidine respectively.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.486-490
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• 1999

In this study, to improve the required properties of tile cement mortar such as excellent water retention capacity (WRC), workability, open time, sag resistance, and tile adhesive strength, tile cement mortars containing the several additives with different ratio were compared and analyzed. By adding small amount of synthesized starch to hydroxypropyl methylcellulose (HPMC) which is used for improving WRC, the decrease of moisture evacuation from mortar surface was observed and the workability of mortar was improved with long open time. Polyacrylamide (PAAm) and ethylencvinyl acetate (EVAc) were also added in order to increase the adhesion of tile. As a results, the saggings of mortar itself and tile were decreased and the adhesive strength of mortar between base and tile was enhanced. By adding melment, the workability was improved by increasing the fluidity of mortar. It is postulated that the properties of tile cement mortar was improved by adding 0.80~1.20% of HPMC, 0.10~0.15% of starch, 0.001~0.015% of PAAm, 0.05~0.10% of EVAc and 0.003~0.005% of melment to the cement mortar.

• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.409-416
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• 1992

The optimum cultural temperature and time for the pullulanase production by Bacillus cereus were $15^{\circ}C$ and 72 hrs, respectively. The addition of casein, nutrient broth and egg albumin to the basal medium, respectively, increased greatly the enzyme production. The enzyme was purified by ammonium sulfate fractionation, CM-cellulose and DEAE-cellulose column chromatographies. The specific activity of the purified enzyme was 29.09 U/mg protein and the yield of enzyme activity was 17.1% The purified enzyme showed a single band on polyacrylamide disc gel electrophoresis and its molecular weight was estimated to be 61,000 by SDSpolyacrylamide disc gel electrophoresis. The isoelectric point for the purified enzyme was pH 7.0. The optimum temperature and pH were $40^{\circ}C$ and 6.5. The purified enzyme was stable below $35^{\circ}C$ and in the pH range of 6.5-11.0. It was greatly inhibited by $Ag^{+}$, $Hg^{2+}$ and $Zn^{2+}$, and its thermal stability was increased by the addition of $Ca^{2+}$ Among various substrates, pullulan was favorably hydrolyzed by the purified enzyme and the hydrolysis product 011 pulluIan was maltotriose.

• Korean Journal of Agricultural Science
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• v.13 no.2
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• pp.299-310
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• 1986

The ovine squamous cell carcinoma (OSCC)-specific and immunosuppressive properties of OSCC extracts were investigated by using the techniques of lymphocyte blastogenicity, acid dissociation-ultrafiltration and gradient polyacrylamide gel electrophoresis. It was found that OSCC extracts contained two major and one minor protein peaks by Sephadex gel fractionation. Two major peaks bear substantial amount of immunoglobulins, antigen-antibody complex and OSCC-specific fractions, and the minor peak includes immunosuppressive materials. OSCC-specific components were detected at the molecular weights of 10,000 to 100,000 daltons in the major peaks and immunosuppressive materials at the fractions with the molecular weight of 10,000 to 100,000 and < 10,000 daltons in the minor peak. When the fractions were further separated by gradient polyacrylamide gel electrophoresis, the OSCC-specific antigens were found in the slice number 4 to 6 in fraction III, and immunosuppressive materials, in the slice numbers 9 to II in fraction V. The present results were considered to provide a basis for preparation and purification of OSCC-specific and immunosuppressive materials from the crude OSCC extracts.