• Journal of fish pathology
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• v.17 no.2
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• pp.131-137
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• 2004

In the present study, phosphatidylcholine (PC) hydrolyzing enzyme had been isolated from membrane of flounder liver. PC hydrolyzing enzyme solubilized in 1% Triton X -100 from membrane was partially purified by sequential chromatography on Heparin Sepharose CL-6B and Heparin-5PW columns. The products by membrane-bound hydrolyzing enzyme were identified as phosphatidic acid and choline, but in the presence of primary alcohol, phosphatidylethanol was produced at the expense of phosphatidic acid. These data suggest that membrane-bound enzyme may be a PC-phosphoipase D (PLD) type. The enzyme had pH optimum at below 6.0 and temperature optimum at $37^\circ{C}$. The activity of PC-PLD was dose-dependently increased by $Ca^{2+}$ but not $Mg^{2+}$. The activity of PC-PLD was stimulate by PC, PIP2 and PE.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.4
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• pp.260-267
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• 2006

The Liquid Culture Assay using a recombinant Agrobacterium tumefaciens strain has been developed as a means for quorum sensing autoinducer screening. However, the low aqueous solubility of marine natural product extracts used as potential autoinducers has been a hindrance in the screening process. Although the addition of organic solvents and/or surfactants could increase aqueous solubility, errors in data interpretation including false positive results could be a serious problem. Therefore, determining the best possible solvent and surfactant at the optimum concentration is crucial. Evaluating methanol, ethanol, 1-propanol, DMSO and DMF at concentration ranges of 0~10% revealed < 2% methanol to be most favorable when tested for ${\beta}$-gal activity and growth inhibition of the recombinant A. tumefaciens strain. On the other hand, among surfactants tested, Triton X-100 was similarly effective in increasing the delivery of autoinducers for activity at less than 0.05% concentration.

• The Korean Journal of Mycology
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• v.20 no.4
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• pp.315-323
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• 1992

The effects of several parameters on PCR amplification in using RAPD were studied. The results of this study suggest that approximately 15 ng of genomic DNA in $20\;{\mu}l$ of reaction mixture results in discrete and reproducible PCR products. In addition, the results indicate that concentration or amounts of reaction components studied are highly inter-dependent in their effects, and RNA can interfere severely with PCR amplification. Suitable concentrations or amounts of reaction components were found to be 30 ng of 10-mer primer, $200\;{\mu}M$ of dNTP, 0.001% gelatin 1.5 mM $MgCl_2$, 10 mM Tris-Cl (pH 8.8), 50 mM KCl, 0.1% Triton X-100, 2 units of Taq DNA polymerase, and 15 ng of RNase-treated genomic DNA in $25\;{\mu}l$ of reaction mixture.

• Journal of Life Science
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• v.23 no.10
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• pp.1246-1251
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• 2013

An organic solvent-tolerant lipase of Pseudomonas sp. BCNU 154 that was isolated from wastewater in the industrial complex region had optimal activity at $37^{\circ}C$ and pH 8. This crude extracellular lipase from BCNU 154 exhibited maximum stability in toluene, retaining about 6.01 U/ml (117.53%) activity for 2 h. $Ca^{2+}$, $Mg^{2+}$, $NH_4{^+}$, and $Na^+$ ions and triton X-100 activated the enzymes, whereas $Ba^{2+}$, $Hg^{2+}$, and $Zn^{2+}$ ions inhibited their activity. Pseudomonas sp. BCNU 154 lipase revealed stable activity comparable to that of the commercial immobilized Novozym 435. Thus, this organic solvent-tolerant lipase could have potential as a whole cell biocatalyst in industrial chemical processes without the use of immobilization.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.1021-1027
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• 1997

We examined some properties of yeast cell wall lytic enzyme produced by Dicyma sp. YCH-37. Several metal ions, reducing reagents, and chemical modifiers have little effects on the lytic activity, except guanidine-HCl. Yeast cells of early log phase were more susceptible to the enzyme than those of stationary phase, and heat-treated cells were more easily lysed than intact living ones. Yeast cells pretreated with organic solvents such as butanol and acetone were more susceptible to the enzyme than intact living ones. Yeast cells cultured in Yeast extract-Malt extract medium containing 0.5 M ammonium sulfate were easily lysed by the lytic enzyme, and yeast cells cultured without shaking were more easily lysed by the enzyme than those with shaking. When SDS, ${\beta}-mercaptoethanol$, Triton X-100, sodium sulfite, and KCl were added to enzyme reaction mixture each, lysis of yeast cells was more effective.

• KSBB Journal
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• v.17 no.1
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• pp.38-43
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• 2002

Characteristics of cell growth and heavymetal adsorption by recombinant Saccharomyus cerevisiae strains harboring multiple copies of the CUP1 gene encoding metallothione (MT) protein were studied in batch cultures. Recombinant S. cerevisiae strains harboring multiple copies of the CUP1 gene were superior to the host and wild-type yeast strains in terms of cell growth and heavy metal removal, indicating that the copy number of the CUP1 gene for MT expression played an important role in the adsorption of heavy metals. It was suggested that the CUP1 promoter for the MT expression is induced by manganese and zinc as well as copper An optimum copper concentration for MT expression and concomitant adsorption of heavy metals by recombinant S. cerevisiae was found to be 0.31 mM. A nonionic surfactant Triton X-100 enhanced cell growth by 17.7% and removal of zinc by 6.1% compared with the control case.

• KSBB Journal
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• v.19 no.2
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• pp.164-167
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• 2004

Cyclodextrin glucanotransferase (EC 2.4.1.19, abbreviated as CGTase) is one of the most applied industrial enzymes that produces cyclodextrins from starch and related ${\alpha}$-1,4-glucans by intramolecular transglycosylation reaction upon Ca$\^$2＋/ dependent manner. The reaction of CLEC, ${\alpha}$-CGTases from Bacillus macerans with the soluble starch as a substrate reveals that the surfactants (SDS, N-octyl-${\beta}$-D-glucoside) significantly affect not only the overall products of CDs but also their selectivity. The surfactants (SDS, Lubrol PX) trigger the increase of ${\alpha}$-CD production, but Triton x-100 and Tween 80 suppress ${\alpha}$-CD specificity. Organic solvents (dimethyl sulfoxide, formamide, 2-methyl-2,4-pentandiol, and ethylene glycol) also cause changes of total product and product selectivity.

• Analytical Science and Technology
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• v.7 no.4
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• pp.427-434
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• 1994

For the analysis of the relatively volatile lead in blood by GFAAS(graphite furnace atomic absorption spectrophotometer), one can not raise the ashing temperature beyond certain degree due to the elevation of the baseline. Previous investigations showed that background is stabilized when the ashing temperature is raised to $700^{\circ}C$ using a matrix modifier. In this study, same result was obtained at the ashing temperature of around $550^{\circ}C$ even when the matrix modifier is not used and only Triton X-100 is used as a diluent, on an instrument which is equipped with both temperature and current controller(Shimadzu, AA-6501S) and thus the temperature control is fast and accurate. Background correction methods of $D_2$ arc and SR(self reversal) were reviewed. The results show that the absorbance is higher for the $D_2$ arc method, but the background correction is higher for the SR method.

• Applied Biological Chemistry
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• v.50 no.1
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• pp.77-81
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• 2007

In order to minimize the mycelial pellet size of a high phosphate-solubilizing fungus, Aspergillus sp. PS-104 in liquid media, one of the critical obstacles during the submerged culture of filamentous fungi, an investigation was focused on the culture conditions (media and inoculum size) and additives (different soils, surfactants and polyethylene glycol 200). When the fungus was cultured in PDB, SDB and YPD media. their pellet sizes decreased in the order of SDB=YPD>PDB. At the higher concentrations of initial inoculum ranging from $1{\times}10^3$ to $1{\times}10^7$ conidia/ml, the smaller size of pellet was formed in the PDB medium. In addition, the pellet size was effectively reduced by 1/6${\sim}$1/4 by the addition of 0.1% soil containing zeolite, diatomite, loess, kaoline and talc, excluding bentonite. The addition of 0.1% Tween 80, Triton X-100 and PEG 200 also decreased the pellet size, but SDS completely inhibited the fungal growth.

• Journal of Microbiology
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• v.33 no.3
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• pp.244-251
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• 1995

An extracellular protease of Salmonella schottmulleri was purified from culture filtrate by using 0-75% ammonium sulfate precipitation, DEAE Sepharose Fast Flow ion exchange chromatography, Ultrogel HA chromatography and Sephacryl S-200 HR molecular sieve chromatography. To measure enzyme activity, synthetic dipeptide substrate (CBZ-arg-arg-AFC) with low molecular weight was employed as substrate. The molecular weight of the purified enzyme was approximately 80 kDa when determined by gel filtration on Sephacryl S-200 HR and 73 kDa when estimated by SDS-PAGE. The isoelectric point was 5.45. The activity of the purified enzyme was inhibited by metal chelating agesnts such as EDTA and 1.10-phenanthroline. The divalent cations, such as Ca$\^$2+/, Zn$\^$2+/, Fe$\^$2+/, Mg$\^$2+/ enhanced its activity. These results suggested that it was a metalloprotease. It had a narrow pH optimum of 6.5-7.5 with a maximum at pH 7.0 and a temperature optimum of 40.deg.C. It was stable at least for 1 week at 40.deg.C and maintained its activity for 24 hours at 50.deg.C, but it was rapidly inactivated at 65.deg.C. This protease was shown to be sensitive to sodium 50.deg.C, but it was rapidly inactivated at 65.deg.C. This protease was shown to be sensitive to sodium 50.deg.C, but it was rapidly inactivated at 65.deg.C. This protease was shown to be sensitive to sodium 50.deg.C, but it was rapidly inactivated at 65.deg.C. This protease was shown to be sensitive to sodium dodecyl sulfate (SDS) and was inactivated in a dose-dependent manner. However, it was resistant to Triton X-100 and the activity was enhanced to 32.3% with treatment of 0.025% Triton X-100.