• Microbiology and Biotechnology Letters
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• v.17 no.1
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• pp.35-45
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• 1989

Streptococcus thermophilus 510 was investigated as n potential source of $\beta$-galactosidase. Optimum cultural conditions for maximum enzyme production were 0.5% loctose as carbon source, initial pH 7.0, 37 $^{\circ}C$, and 18 hours of cultivation. The enzyme was purified to homogeneity by ammonium sulfate fractionation, protamine sulfate precipitation, Sephadex G-200 gel filtration, and DEAE-Sephadex A-50 ion exchange chromntography. The purified enzyme exhibited an optimum pH at 1.0, and an optimum temperature of 5$0^{\circ}C$. Metal ions such as Mn$^{2+}$ and $K^+$, dithiothreitol, and 2-mercaptoethanol stimulated $\beta$-galactosidase activity. Ethylenediamine tetraacetic add, 8-hydroxyquinoline, Hg$^2+$, Zn$^{2+}$, Co$^{2+}$, $Ca^{2+}$, and galactose were inhibitory. The $K_m$ and V$_{max}$ for o-nitrophenyl $\beta$-D-galactopyranoside were 1.25mM and 88.50$\mu$moles/min.mg protein, respectively. The molecular weight was estimated to be 520,000, and the amino acid composition indicated relatively high contents of glutamic acid, aspartic acid, leucine, and valine.

• Journal of Korean Society on Water Environment
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• v.21 no.4
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• pp.403-409
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• 2005

Methyl tert-butyl ether (MTBE) contamination in groundwater often coexists with benzene, toluene, ethylbenzene, and xylene (BTEX) near the source of the plume. Then, groundwater contamination problems have been developed in areas where the chemical is used. Common sources of water contamination by BTEX and MTBE include leaking underground gasoline storage tanks and leaks and spills from above ground fuel storage tanks, etc. In oil-contaminated environments, anaerobic biodegradation of BTEX and MTBE depended on the concentration and distribution of terminal electron acceptor. In this study, effect of electron acceptor on the anaerobic biodegradation for BTEX and MTBE-contaminated soil was investigated. This study showed the anaerobic biodegradation of BTEX and MTBE in two different soils by using nitrate reduction, ferric iron reduction and sulfate reduction. The soil samples from the two fields were enriched for 65 days by providing BTEX and MTBE as a sole carbon source and nitrate, sulfate or iron as a terminal electron acceptor. This study clearly shows that degradation rate of BTEX and MTBE with electron acceptors is higher than that without electron acceptors. Degradation rate of Ethylbenzene and Xylene is higher than that of Benxene, Toluene, and MTBE. In case of Benzene, Ethylbenzene, and MTBE, nitrate has more activation. In case of Toluene and Xylene, sulfate has more activation.

• Journal of the Korean Ceramic Society
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• v.44 no.9
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• pp.471-476
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• 2007

The hydration mechanism of the $3CaO{\cdot}Al_2O_3-CaSO_4{\cdot}2H_2O$ system in the presence of alkali sulfates has been investigated. The early hydration rate of $3CaO{\cdot}Al_2O_3$ was accelerated by the addition of $Na_2SO_4$ and $K_2SO_4$. This is closely related to the formation of syngenite $(CaSO_4{\cdot}K_2SO_4{\cdot}H_2O)$, and the U-phase added $K_2SO_4$ and $Na_SO_4$ in the $3CaO{\cdot}Al_2O_3-CaSO_4{\cdot}2H_2O$ system, respectively. The formation of the rigid syngenite and U-phase structure led to rapid setting and decreases the sulfate content in the liquid phase of the hydrating cement to the extent that it cannot adequately retard the hydration of $3CaO{\cdot}Al_2O_3$. In case of the alkali sulfate not added to the $3CaO{\cdot}Al_2O_3-CaSO_4{\cdot}2H_2O$ system, the ettringite was transformed to monosulfoaluminate immediately after the consumption of gypsum. However, when the alkali sulfates were added to this system, the ettringite did not transform to monosulfoaluminate immediately even though the gypsum was completely consumed. There was a stagnation period to transform to the monosufoaluminate after the consumption of gypsum because the syngenite and U-phase remained as the sulfate source.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2004.11a
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• pp.26-27
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• 2004

This study was conducted to evaluate the value of chicken keel cartilage as a source of mucopoly-saccharide-protein containing chondroitin sulfate (CS) and to find the optimum extraction conditions. The hot water extraction and alcalase hydrolysis methods were performed for extraction mucopolysaccharide in lyophilized chicken keel cartilage. The most efficient condition was hydrolysis with 2 % alcalase in 10 volumes of distilled water for 120 min. The yield of hydrolysate and CS content were 75.87 % and 25.61 %, respectively. For further separation of CS from hydrolysate by alcalase, ethanol precipitation was performed. The yield of ethanol precipitate and its CS content were 21.41 % and 46.31 %, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.11 no.2
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• pp.31-35
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• 1982

Alcohol fermentation was carried out by using the yeast (S. cerevisiae) and soybean whey as the sole carbon source. The whey was gained form waste after manufacturing of soybean curd. The whey contained approximately one gram sugar per hundred mililter and the sugar was consisted of a 65 per cent of reducing sugar. However, it showed a low protein content of 43mg per the same volume. Ammonium sulfate showed the best effect on the generation of carbon dioxide among three kinds of tested nitrogen sourogen sources, potassium nitrate, urea and ammonium sulfate. Thus, fermentation was carried out with supplement of 2.0g ammonium sulfate to one liter of soybean whey. During fermentation continued for 48 hours, the maximum amount of ethanol 1.86g was produced from one liter of soybean whey. The ethanol fermentation utilized 81 and 94% of its initial sugar and protein contents, respectively.

• Journal of the Korean Applied Science and Technology
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• v.22 no.3
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• pp.212-218
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• 2005

Most of cosmetics are emulsion products that contain the source of nutrition vegetable oil, mineral oil, natural extract and carbohydrate etc. There are many possibilities to be contaminated by microbials. We investigated the effect of antimicrobial and minimum inhibitory concentration(MIC) with thiamine dilauryl sulfate(TDS), which was prepared to use cosmetic lotion formulation. Staphylococcus aureus(S. aureus) and Escherichia col(E. coli) were used as test organism. MIC value of TDS was determined aganist microorganism for the growth inhibition by concentration of TDS. From the MIC results, antimicrobial effect of TDS was generally more effective to gram positive than gram negative. Antimicrobial effect with pH value against some microorganism appeared in the following order : pH 5 > pH 6 > pH 7. It showed strong antimicrobial activities against S. aureus, and weak antimicrobial activities against E. coli. If it was possible to determine the formulations with TDS, it would be effective to reduce the artificial preservatives.

• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.967-971
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• 2004

The kinetics of sulfite uptake were examined in a wild-type laboratory strain of Saccharomyces cerevisiae to determine if carrier-mediated sulfite uptake involved a proton symport, as previous studies on sulfite uptake have suggested both an active process and facilitated diffusion. Accumulation of intracellular sulfite was initially rapid and linear up to 50 sec. Uptake was saturable at final concentrations equal to or greater than 3 mM sulfite, and increased 2-fold in the presence of 2% glucose. Uptake was significantly reduced in cells pretreated with 100-500 $\mu$M carbonyl cyanide mchlorophenylhydrazone (CCCP) or 2,4-dinitrophenol (DNP), both of which dissipate proton gradients. Uptake was also significantly inhibited in the presence of 1 mM arsenate, an inhibitor of ATP synthesis. Extracellular alkalization was observed in cells incubated with 1-2 mM sulfite in a weak tartrate buffer at pH 3.5 and 4.5. These findings suggest that the bisulfite ion, $HSO_3^-$, an anionic form of sulfite, is taken up by a carrier-mediated proton symport. A met16 sull sul2 mutant, impaired in both sulfite formation and sulfate uptake, was found able to grow on a medium with sulfite as the sole Sulfur source, indicating that the sulfate transporters Sul1p and Sul2p are not required for sulfite uptake.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.872-877
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• 2009

By-products of marine organisms including salmon, skate, flatfish, and yellow goosefish were investigated to search for new source of chondroitin sulfate (CS). Agarose gel electrophoresis with chondroitinase depolymerization showed that purified chondroitin sulfate did not contain any other glycosaminoglycans. 1H-nuclear magnetic resonance (NMR) spectra were acquired to confirm the structure and purity. The average molecular weight ranging from 22 to 64 kDa was determined by high performance size exclusion chromatography. Disaccharide compositions and purities were determined by strong anion exchange-high performance liquid chromatography (SAX-HPLC) after chondroitinase ABC depolymerization. SAX-HPLC data exhibited that the purity was from $81.7{\pm}1.3$ to $114.2{\pm}2.5%$ and the yield was from 1.3 to 12.5%. All analytical results indicate that salmon cartilage, skate cartilage, and yellow goosefish bone could be promising sources of CS to substitute shark cartilage CS in commercial neutraceuticals.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.227-233
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• 1998

To mitigate the methane emission from rice paddy fields, effects of nitrogen fertilizers source and cultural patterns were evaluated on silty loam soils. And a pot experiment was carried out to find out the effects of nitrogen fertilizers on soil pH, Eh, sulfate concentration of soil water in flooded soil. In transplanting cultivation, the total methane emission depending on fertilizers was $32.9gm^{-2}$ for urea ; $30.3gm^{-2}$ for ammonium sulfate ; $26.4gm^{-2}$ for coated urea. Methane emitted in direct seeding on dry soil was $24.7gm^{-2}$ for urea ; $16.7gm^{-2}$ for ammonium sulfate : and $22.8gm^{-2}$ for coated urea. Thus, the methane emission rate of direct seeding on dry soil was 29.7% lower than transplanting. According to the nitrogen fertilizers, the methane emission rate by ammonium sulfate and coated urea were reduced 18.4 and 15.9% in comparison with urea, respectively. In pot experiments, pH in flooded soils depending on nitrogen fertilizers dereased in order of urea > coated $urea{\fallingdotseq}no$ fertilizer > ammonium sulfate and the order was coincided with that of total $CH_4$ emission from flooded soil. Soil Eh was highest in ammonium sulfate application followed by coated urea, no fertilizer, urea. And sulfate concentrations of soil water were in order of ammonium sulfate > coated urea > urea > no fertilizer.

• Asian Journal of Atmospheric Environment
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• v.8 no.3
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• pp.115-125
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• 2014

In this study, particle composition data for $PM_{10}$ samples were collected every 3 days at Seoul, Korea from August 2006 to November 2007, and were analyzed to provide source identification and apportionment. A total of 164 samples were collected and 21 species (15 inorganic species, 4 ionic species, OC, and EC) were analyzed by particle-induced x-ray emission, ion chromatography, and thermal optical transmittance methods. Positive matrix factorization (PMF) was used to develop source profiles and to estimate their mass contributions. The PMF modeling identified nine sources and the average mass was apportioned to secondary nitrate (9.3%), motor vehicle (16.6%), road salt (5.8%), industry (4.9%), airborne soil (17.2 %), aged sea salt (6.2%), field burning (6.0%), secondary sulfate (16.2%), and road dust (17.7%), respectively. The nonparametric regression (NPR) analysis was used to help identify local source in the vicinity of the sampling area. These results suggest the possible strategy to maintain and manage the ambient air quality of Seoul.