• Journal of Microbiology and Biotechnology
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• v.21 no.10
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• pp.1012-1020
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• 2011

A gene coding for an endoglucanase (EglA), of the glycosyl hydrolase family 12 and derived from Aspergillus niger VTCC-F021, was cloned and sequenced. The cDNA sequence, 717 bp, and its putative endoglucanase, a 238 aa protein with a predicted molecular mass of 26 kDa and a pI of 4.35, exhibited 98.3-98.7% and 98.3-98.6% identities, respectively, with cDNA sequences and their corresponding endoglucanases from Aspergillus niger strains from the GenBank. The cDNA was overexpressed in Pichia pastoris GS115 under the control of an AOX1 promoter with a level of 1.59 U/ml culture supernatant, after 72 h of growth in a YP medium induced with 1% (v/v) of methanol. The molecular mass of the purified EglA, determined by SDS-PAGE, was 33 kDa, with a specific activity of 100.16 and 19.91 U/mg toward 1% (w/v) of ${\beta}$-glucan and CMC, respectively. Optimal enzymatic activity was noted at a temperature of $55^{\circ}C$ and a pH of 5. The recombinant EglA (rEglA) was stable over a temperature range of $30-37^{\circ}C$ and at pH range of 3.5-4.5. Metal ions, detergents, and solvents tested indicated a slightly inhibitory effect on rEglA activity. Kinetic constants ($K_m$, $V_{max}$, $k_{cat}$, and $k_{cat}/K_m$) determined for rEglA with ${\beta}$-glucan as a substrate were 4.04 mg/ml, 102.04 U/mg, 2,040.82 $min^{-1}$, and 505.05, whereas they were 10.17 mg/ml, 28.99 U/mg, 571.71 $min^{-1}$, and 57.01 with CMC as a substrate, respectively. The results thus indicate that the rEglA obtained in this study is highly specific toward ${\beta}$-glucan. The biochemical properties of rEglA make it highly valuable for downstream biotechnological applications, including potential use as a feed enzyme.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.4 s.48
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• pp.525-532
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• 2004

N-acyl taurates are known as environmental-friendly and non-irritating to skin. In this study, the physicochemical properties of N-acyl taurates, which are amide-type anionic surfactants, were measured and also compared with sulfate-type anionic surfactants that show low biodegradability and are highly irritating to skin. The possibility of replacing the currently existing sulfate-type surfactants by N-acyl taurates was examined. Based on the experimental results, shampoos were formulated with these anionic surfactants and their stability and properties were measured. The possibility of application of amide-type surfactants to personal care cleaner was evaluated. Experimental results show that N-acyl taurates have various favorable aspects in making personal care cleanser: high viscosity, low surface tension, and low CMC values. These properties of N-acyl taurates generate nano-scale particles in emulsion, which is stable due to its high viscosity. This emulsion also has good cleaning ability with small amount of usage due to easy penetration into contaminants. Shampoo with N-methyl oleyl taurate showed high yield point and constant viscosity, and formed stable emulsion with nano- scale uniform particles. These results suggest that N-acyl taurates play an important role in making stable Interior structure in shampoo, and which improves the storage property.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.2
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• pp.139-145
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• 2012

There is a unique type of fatty acid in the hair surface. 18-methyleicosanoic acid (18-MEA) is an unusual anteiso fatty acid covalently linked to the outermost surface of hair cuticle. A layer of 18-MEA is located in the upper ${\beta}$-layer of the CMC that is responsible for the low surface energy and low friction resistance of the hair's outer surface. The high mobility of 18-MEA molecule facilitates spreading of extraneous lipid by decreasing interfacial shear strength. In this study, we introduced N-hydroxyl succinimidyl ester functional group to the one end of C10 - 40 isoalkyl acid for regenerating hair surface with covalently bound fatty acid layer. The re-hydrophobicization of hair surface has been investigated by contact angle measurement. The inner moisture content of hair at different levels of humidity (40, 55, 70 %RH) was measured by electric moisture analyzer. Treatment with Hydroxysuccinimidyl C10 - 40 Isoalkyl Acidate (HCIA) was supposed to make hair surface smoother by filling the cracks between cuticles with covalently bound fatty acid monomolecular layer like cuticle glue. This glue effect was also confirmed with line profile of AFM images. Therefore, the moisture and structural components of inner hair were not easily flown out and the optimum moisture content could be kept constantly though the outside humidity level was changed. The lateral force microscopy (LFM) by using atomic force microscope showed that the friction force of hair surface treated with HCIA was decreased. It also showed the constantly sustained friction value even after shampooing repeated 15 times.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.3
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• pp.159-163
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• 2007

The relationship between texture and rheological properties of mascara(oil-in-water emulsion) was analyzed in this study. The final mascara product and gelling agents(2.0 wt%) used therein, such as hydroxyethylcellulose(HC), carboxymethylcellulose(CMC), hectorite, sodium magnesium silicate (SMS), hydroxyethyl acrylate/sodium acryloyldimethyl taurate copolymer(HS), and polyacrylate 13/polyisobutene/polysorbate 20 (PPP), were measured for rheological properties. As a result, HS and PPP showed the highest adhesiveness which were related to the volumizing effect of mascara. The viscosities of HC, SMS, and HS were measured at the stress range of $1{\sim}1,000s^{-1}$. SMS, with the lowest storage modulus range of $100{\sim}1,000s^{-1}$, affected the mascara in terms of smooth texture. The results of this study suggest that the rheology of gelling agents used influences the final texture of the mascara.

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.568-574
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• 1997

The effect of microencapsulation of maetal hydride (MH) with copper on the electrode performance of a Ni/MH battery has been investigated. The MH electrodes were prepared with a combination of cold press and paste methods. The discharge capacity of the electrode increased with an addition of small amounts if CMC into the electrode, but decreased when heat-treated in an oxygen-free nitrogen flow. The capacity of a Cu-coated $LaNi_5$ electrode was higher than that of LaNi5electrode. The discharge capacity of the electrode prepared with Cu-coated $LaNi_5$ increased with the increase of copper content in the electrode. It is considered that the increase of copper content enhanced the current density on the electrode surface, leading to the increase of the discharge capacity The MH electrode coated by an acidic electroless plating method showed much higher discharge capacity than that using an alkaline electroless plating method. The discharge capacity of the $LaNi_{4.5}Al_{0.5}$ electrode was higher than that of the $LaNi_5$ electrode. Also, the effect of microencapsulation on the deactivation of $LaNi_5$ was studied using an absorption-desorption cycle in CO-containing hydrogen.

• Applied Chemistry for Engineering
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• v.27 no.3
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• pp.291-298
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• 2016

In this study, zwitterionic surfactants were added to liposome systems at different pH conditions to understand the effect of surfactants on liposome characteristics. For this purpose, amine oxide surfactants having different hydrocarbon chain lengths were synthesized and the structure of the resulting product was elucidated by using $^1H$ NMR, $^{13}C$ NMR, and FT-IR. In addition, the physical properties of newly synthesized surfactants such as critical micelle concentration (CMC), surface tension and isoelectric point were measured. The stability characteristics of liposome systems including average particle sizes and zeta potentials were measured by varying pH and hydrocarbon chain lengths of an amine oxide surfactant. Effects of the pH and hydrocarbon chain length of an amine oxide surfactant on fluidity of a liposome membrane were also examined by measuring the deformability and the binding degree between the surfactant and liposome.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4435-4440
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• 2013

Aloe vera gel supercritical $CO_2$ extract (AVGE) has been shown to contain five phytosterols, reduce visceral fat accumulation, and influence the metabolism of glucose and lipids in animal model experiments. Recent epidemiologic studies have shown that obesity is an established risk factor for several cancers including colorectal cancer. Therefore, we examined the effects of AVGE on intestinal polyp formation in Apc-deficient Min mice fed a high-fat diet. Male Min mice were divided into normal diet (ND), high fat diet (HFD), low dose AVGE (HFD+LAVGE) and high dose AVGE (HFD+HAVGE) groups. The ND group received AIN-93G diet and the latter 3 groups were given modified high-fat AIN-93G diet (HFD) for 7 weeks. AVGE was suspended in 0.5% carboxymethyl cellulose (CMC) and administered orally to mice in HFD+LAVGE and HFD+HAVGE groups every day (except on Sunday) for 7 weeks at a dose of 3.75 and 12.5 mg/kg body weight, respectively. ND and HFD groups received 0.5% CMC alone. Between weeks 4 and 7, body weights in the HFD and HFD+LAVGE groups were reduced more than those in the ND group. However, body weights were not reduced in the HFD+HAVGE group. Mice were sacrificed at the end of the experiment and their intestines were scored for polyps. No significant differences were observed in either the incidence and multiplicity of intestinal polyps (${\geq}0.5$ mm in a diameter) among the three groups fed HFD. However, when intestinal polyps were categorized by their size into 0.5-1.4, 1.5-2.4, or ${\geq}2.5$ mm, the incidence and multiplicity of large polyps (${\geq}2.5$ mm) in the intestine in the HFD+HAVGE group were significantly lower than those in the HFD group. We measured plasma lipid (triglycerides and total cholesterol) and adipocytokine [interleukin-6 and high molecular weight (HMW) adiponectin] levels as possible indicators of mechanisms of inhibition. The results showed that HMW adiponectin levels in the HFD group were significantly lower than those in the ND group. However, the levels in the HFD+HAVGE group were significantly higher than those in the HFD group. These results indicate that HAVGE reduced large-sized intestinal polyps and ameliorated reduction in plasma HMW adiponectin levels in Min mice fed HFD.

• 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.

• KSBB Journal
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• v.17 no.2
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• pp.195-202
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• 2002

The production conditions of cellulolytic enzymes by a fungus, strain FJ1, were optimized using response surface analysis. The culture factors which largely affected the production of enzymes such as cultivation time, carbon source concentration, nitrogen source concentration, and composition ratio of carbon sources were employed. Optimizedconditions of the factors above corresponding to each cellulolytic enzyme production were as fellowing: CMCase production was obtained in the conditions of cultivation time of 5.4 days, carbon source concentration of 3.5%, nitrogen source concentration of 0.6%, and composition ratio of carbon sources of 52:48 (avicel:CMC), xylanase appeared in the conditions of 5.3 days, 3.5%, 0.8%, and 54:46, respectively, and $\beta$-glucosidase were 7.0 days, 5.0%, 1.0%, and 83:17, respectively, and avicelase were 6.5 days, 4.0%, 0.9%, and 64:36, respectively. The activities of CMCase, xylanase, p-glucosidase, and avicelase predicted by the response surface methodology were 33.5, 52.6, 2.88, and 1.84 U/mL, respectively, and $\beta$-glucosidase activity was enhanced up to 74% when compared to that obtained in the experimental conditions.

• Journal of Mushroom
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• v.15 no.3
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• pp.134-138
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• 2017

The white button mushroom, Agaricus bisporus, is commercially the fifth most important edible mushroom, accounting for the production of 9,732 tons of mushrooms in Korea in 2015. The genus Agaricus has been known for its potential to degrade lignocellulosic materials. Chemical analyses carried out during the cultivation of A. bisporus indicated that the cellulose, hemicellulose, and lignin fractions were changed preferentially for both vegetative growth and sexual reproduction. We screened A. bisporus strains for effective biodegradation through extracellular enzyme activity using cellulase, xylanase, and ligninolytic enzymes. The enzyme biodegradations were conducted as follows: mycelia of collected strains were incubated in 0.5% CMC-MMP (malt-mops-peptone), 0.5 Xylan-MMP, and 0.5% lignin-MMP media for 14 days. Incubated mycelia were stained with 0.2% trypan blue. Eighteen strains were divided into 8 groups based on different extracellular enzyme activity in MMP media. These strains were then incubated in sterilized compost and compost media for 20 days to identify correlations between mycelial growth in compost media and extracellular enzyme activity. In this study, the coefficient of determination was the highest between mycelial growth in compost media and ligninolytic enzyme activity. It is suggested that comparison with ligninolytic enzyme activity of the tested strains is a simple method of screening for rapid mycelial growth in compost to select good mother strains for the breeding of A. bisporus.