• Bulletin of the Korean Chemical Society
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• v.18 no.3
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• pp.300-305
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• 1997

Effect of a nonionic surfactant, Tween 20 on the adsorption and kinetic mechanism for the hydrolysis of a microcrystalline cellulose, Avicel PH 101, by endoglucanase Ⅰ (Endo Ⅰ) and exoglucanase Ⅱ (Exo Ⅱ) isolated from Trichoderma viride were studied. The Langmuir isotherm parameters, amount of maximum adsorption (Amax) and adsorption equilibrium constant (Kad) for the adsorption, were obtained in the presence and the absence of nonionic surfactant. On the addition of Tween 20, the Kad and Amax values of Exo Ⅱ were decreased, while those of Endo Ⅰ were not affected. These indicate that the adsorption affinity of Exo Ⅱ on the cellulose is weakened by nonionic surfactant, and the surfactant enhanced desorption of Exo Ⅱ from insoluble substrate. The enzymatic hydrolysis of the cellulose can be described by two parallel pseudo-first order reactions using the percentages of easily (Ca) and hardly (Cb) hydrolyzable cellulose in Avicel PH 101 and associated rate constants (ka and kb). The Ca value was increased by adding Tween 20 for all enzyme samples (Exo Ⅱ, Endo Ⅰ and their 1:1 mixture) implying that the low-ordered crystalline fraction in the cellulose may be partly dispersed by surfactant. The ka value was not affect by adding Tween 20 for all enzyme samples (Exo Ⅱ, Endo Ⅰ and their 1:1 mixture). The kb value of Exo Ⅱ was increased by adding Tween 20, while that of Endo Ⅰ was not affected. This suggests that the surfactant helps the Exo Ⅱ desorb from microcrystalline cellulose, and increase the hydrolysis rate. These results were show that the increase of hydrolysis of cellulose by the nonionic surfactant is due to both the activation of Exo Ⅱ and partial defibrillation of the cellulose.

• Journal of the Korean Chemical Society
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• v.56 no.5
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• pp.556-562
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• 2012

The critical micelle concentration (CMC) and the counter-ion binding constant (B) for the mixed micellizations of TTAB (tetradecyltrimethylammonium bromide) with other surfactants (DTAB, CTAB, Tween-20, Tween-40, and Tween-80) in aqueous solution of 4-chlorobenzoic acid (0.5 mM) at $25^{\circ}C$ were determined as a function of ${\alpha}_1$ (the overall mole fraction of TTAB) by using the spectrophotometric method and the conductivity method. Various thermodynamic parameters ($X_i$, ${\gamma}_i$, $C_i$, $a_i^M$, ${\beta}$, and ${\Delta}H_{mix}$) were calculated for each mixed surfactant system and compared with the other mixed surfactant systems by means of the equations derived from the nonideal mixed micellar model. The results show that TTAB/DTAB mixed system has a great positive deviation from the ideal mixed micellar model and the other mixed systems have great negative deviations from the ideal mixed model.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.198-201
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• 2000

The capacity of micelle formation between astaxanthin and various surfactants was compared. Tween 20 was identified the most suitable surfactant in terms of astaxanthin extraction capacity. The ethylene oxide group of Tween 20 was identified as the most significant factor to increase the HLB value that determined the extraction capacity. The effect of micelle formation condition, such as molar ratio of astaxanthin and Tween 20, pH and ionic strength was also investigated. pH and ionic strength showed no significant effects. Antioxidant activity of astaxanthin was twice of ${\alpha}-tocopherol$ and 4 times of ${\beta} -carotene$. Crude astaxanthin extract from the yeast cell seemed to be less degraded than pure astaxanthin by air and light exposure, probably because of the presence of other carotenoids and lipids. Under the optimal conditions, the molar ratio of micelle formed was found to be 1 : 12 for astaxanthin : Tween 20.

• KSBB Journal
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• v.17 no.2
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• pp.176-181
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• 2002

Astaxanthin (3,3＇-dihydroxy-${\beta}$, ${\beta}$-carotene-4-4＇-dione), a natural pigment of pink to red color, is widely distributed in nature particularly in the skin layer of salmonoids and the crust of shrimp, lobster, etc. Recently, it was produced from the yeast culture of Phaffia rhodozyma. Because of its high thermal stability and antioxidant functionality, its applications can be extended into food, cosmetics, and pharmaceutical ingredient beyond the traditional feed additive. Because of its very high lipophilicity, astaxanthin has been extracted traditionally by strong organic solvents such as chloroform, petroleum ether, acetone, etc. In this study, we developed a surfactant-based solubillization system for astaxanthin, and used it to extract astaxanthin from disrupted yeast cells. Among Tween 20, Triton X-100 and SDS, Tween 20 was identified as the most suitable surfactant in terms of extraction capacity and safety. The ethylene oxide group of Tween 20 was identified as the most significant factor to increase the HLB value that determined the extraction capacity. The effects of micelle formation condition, such as the molar ratio of astaxanthin and Tween 20, pH, and ionic strength were also investigated. pH and ionic strength showed no significant effects. The optimal molar ratio between astaxanthin and Tween 20 was 1 : 12. Antioxidant activity of astaxanthin was higher than ${\beta}$-carotene and ${\alpha}$-tocopherol. Astaxanthin in the crude extract from the yeast cell was more resistant to air and/or light degradation than pure astaxanthin, probably because of the presence of other carotenoids and lipids.

• Applied Chemistry for Engineering
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• v.18 no.5
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• pp.501-505
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• 2007

Organophosphorus hydrolase (OPH) expressed from recombinant Escherichia coli was used to biodegrade organophosphate insecticide coumaphos which has a very high toxicity in mammalian cells. To improve the productivity of OPH, the effects of nonionic surfactants (Tween 20, PEG 1000) and organic solvents, such as glycerol, propanol, and ethanol, were investigated in the strain culture. The maximum OPH was produced when the 0.25% of Tween 20 and 0.5% of glycerol were added to the medium. As the OPH obtained from disrupt-cell process by ultrasound treatment was used, the biodegradation efficiencies of 0.2, 0.5, 1.0 and 2.0 mM coumaphos were 100, 88, 84 and 78%, respectively. A novel method developed in this study could be applied to the biodetoxification technology in the contaminated region with various coumaphos concentration.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1566-1570
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• 2012

The combined use of indium and polysorbate 20 (Tween 20) was considered as a new inhibition technique for zinc corrosion. Zn and Zn-In alloy coatings were prepared by electrodeposition and their morphology and composition were characterized by scanning electron microscopy (SEM) and inductively coupled plasma atomic emission spectrometry (ICP-AES). The corrosion inhibition effect of indium and Tween 20 on zinc was investigated by polarization curves and electrochemical impedance spectroscopy (EIS). The corrosion inhibition efficiencies obtained from Tafel and EIS analyses are well in agreement. Zinc corrosion can be inhibited to some extent by the individual use of indium and Tween 20 and higher corrosion inhibition efficiency can be obtained by the combined use of indium and Tween 20.

• Biotechnology and Bioprocess Engineering:BBE
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• v.2 no.2
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• pp.94-96
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• 1997

A xylanase was purified from a commercial crude xylanase, Pulpzyme HC, and used for the bleaching of kraft pulp in the absence or in the presence of nonionic surfactants, Tween 20, Tween 80, and Igepal C930. The purified xylanase has a molecular weight of 23,500 as determined by a reducing SDS-PAGE. Tween 20 was most effective to enhance the efficiency of the enzymatic bleaching of kraft pulp by xylanase.

• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.439-449
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• 2000

This study was to investigate the expression of transgene after co-injection of spermatozoon and EGFP gene into mature oocytes in cattle. From frozen semen, spermatozoa were treated by DTT with 0.03% Tween-20, freezing and thawing or 0.02% Triton X-100 to disrupt their plasma membranes. The sperm injected oocytes were co-cultured with bovine oviduct epithelial cells in CRlaa, and expression of EGFP in embryos were observbed under epifluorescent microscope. Two pronuclei were formed in oocytes injected with sperm treated by DTT (44.6%), DTT-Tween-20 (48.4%), DTT-freezing (44.4%) and DTT-Triton X-100 (42.9%). Cleavage and blastocyst formation rates of bovine oocytes which injected with sperm treated by DTT, DTT-Tween-20, DTT-freezing, and DTT-Triton X-100 were 49.1, 58.5, 43.9, and 48.4% and 10.2, 13.0, 6.8, and 6.5%, respectively. Although the most of embryos were showing mosaicism, embryos expressing EGFP gene were observed in all treated groups. Therefore, these results indicate that membrane disrupted sperm could interact with exogenous DNA, and that this procedure may be useful to introduce foreign gene into bovine oocytes.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.5
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• pp.462-465
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• 2006

An important issue in the oxidation of pentachlorophenol (PCP) by the enzyme horseradish peroxidase (HRP) is enzyme inactivation during the reaction. This study was initiated to investigate the ability of two nonionic surfactants (Tween 20 and Tween 80) to mitigate HRP inactivation. The surfactants were tested at concentrations below and above their critical micelle concentrations (CMCs). Enhancement of PCP oxidation was observed at sub-CMCs, indicating effective protection of HRP by the two surfactants. Maximum levels of PCP removal were observed when the concentrations of Tween 20 and Tween 80 were 40 and 50% of the CMCs, respectively At supra-CMCs, both surfactants caused a noticeable reduction in the extent of PCP removal.

• Environmental Engineering Research
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• v.16 no.4
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• pp.219-225
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• 2011

The objective of this study was to investigate the bacterial adhesion to iron (hydr)oxide-coated sand (IHCS) and aluminum oxidecoated sand (AOCS) in the presence of Tween 20 (nonionic surfactant) and lipopeptide biosurfactant (anionic surfactant) through column experiments. Results show that in the presence of Tween 20, bacterial adhesion to the coated sands was slightly decreased compared to the condition of deionized water; the mass recovery (Mr) increased from 0.491 to 0.550 in IHCS and from 0.279 to 0.380 in AOCS. The bacterial adhesion to the coated sands was greatly reduced in lipopeptide biosurfactant; Mr increased to 0.980 in IHCS and to 0.797 in AOCS. Results indicate that the impact of lipopeptide biosurfactant on bacterial adhesion to metal oxide-coated sands was significantly greater than that of Tween 20. Our results differed from those of the previous report, showing that Tween 20 was the most effective while the biosurfactant was the least effective in the reduction of bacterial adhesion to porous media. This discrepancy could be ascribed to the different surface charges of porous media used in the experiments. This study indicates that lipopeptide biosurfactant can play an important role in enhancing the bacterial transport in geochemically heterogeneous porous media.