• Microbiology and Biotechnology Letters
• /
• v.34 no.4
• /
• pp.311-317
• /
• 2006

Using PCR amplification, we cloned a cellulase gene (ce/H) from the Bacillus subtilis AH18 which has plant growth-promoting activity and antagonistic ability against pepper blight caused by Phytophthora capsici. The 1.6 kb PCR fragment contained the full sequence of the cellulase gene and the 1,582 bp gene deduced a 508 amino acid sequence. Similarity search in protein database revealed that the cellulase of B. subtilis AH18 was more than 98% homologous in the amino acid sequence to those of several major Bacillus spp. The ce/H was expressed in E. coli under an IPTG inducible lac promoter on the vector, had apparent molecular weight of about 55 kDa upon CMC-SDS-PAGE analysis. Partially purified cellulase had not only cellulolytic activity toward carboxymethyl-cellulose (CMC) but also insoluble cellulose, such as Avicel and filter paper (Whatman No. 1). In addition, the cellulase could degrade a fungal cell wall of Phytophthora capsici. The optimum pH and temperature of the ce/H coded cellulase were determined to be pH 5.0 and $50^{\circ}C$. The enzyme activity was activated by $AgNO_3$ or $CoCl_2$. However its activity was Inhibited by $HgC1_2$. The enzyme activity was activated by hydroxy urea or sodium azide and inhibited by CDTA or EDTA. The results indicate that the cellulase gene, ce/H is an antifungal mechanism of B. subtilis AH18 against phytophthora blight disease in red-pepper.

• Journal of the Korean Ceramic Society
• /
• v.39 no.6
• /
• pp.582-588
• /
• 2002

IrO$_2$-RuO$_2$ films were deposited on plasma sprayed TiO$_2$ buffer layer above Ti metal by sol-gel and dip-coating method. Organic vehicle (ethyl cellulose and $\alpha$-terpineol) and glass frit were added to improve adherence of the coatings. Taguchi method and L$_{18}$ (2$^1$$\times$3$^{7}$ ) orthogonal arrays were evalvated in terms of current density to determine the optimal combination of levels of factors that best satisfy the bigger is better quality characteristic. The observed conditions were as fellows: ethyl cellulose (100 cp), drying temperature and time (17$0^{\circ}C$,20 min), heat treatment temperature and time (75$0^{\circ}C$,10 min), the weight ratio of IrO$_2$-RuO/powders to glass frit (99:5), final heat treatment time (120 min) and flow rate of air (5 sccm), respectively. ANOVA analysis suggested that the influence of the factors within $\alpha$= 0.1 was significant with a 90% confidence level.

• The Korean Journal of Mycology
• /
• v.17 no.3
• /
• pp.145-148
• /
• 1989

An acid-stable ${\alpha}-amylase$ produced by Aspergillus niger K-25 strain was purified by fractional precipitation with ammonium sulfate, ethacridine and acetone. The final preparation was homogeneous in cellulose acetate electrophoresis. The enzyme retained 91 % of its oringinal activity at pH 3.0, 8.7% at pH 2.4. The optimum pH of the enzyme was around pH 4. The purified-enzyme with optimum temperature of $40^{\circ}C$ was more heat-stable than the commercial product. The enzyme retained 80% of its original activity when heated to $60^{\circ}C$ for 30 minutes while the commercial amylase lost its acitivity completely within 30 minutes at $50^{\circ}C$.

• Journal of Microbiology and Biotechnology
• /
• v.1 no.2
• /
• pp.90-95
• /
• 1991

A ${\alpha}-galactosidase{\;}({\alpha}-D-galactoside$ galactohydrolase; EC 3.2.1.22) was purified from the culture filtrate of Penicillium purpurogenum by DEAE-cellulose column chromatography, gel filtration of Bio gel p-l00, and subsequent SP-Sephadex C-25 chromatography. The final preparation thus obtained showed a single band on polyacrylamide disc-gel and SDS-polyacrylamide gel electrophoresis. The molecular weight and isoelectric point were determined to be 63,000 and pH 4.0 by SDS-polyacrylamide gel electrophoresis and isoelectric focusing, respectively. The galactosidase exhibited maximum activity at pH 4.5 and $55^{\circ}C$, and was stable between pH 2 and 5, and also stable up to $40^{\circ}C$. The enzyme activity was not affected considerably by treatment with other metal compounds except mercuric chloride and silver nitrate. Copra galactomannan was finally hydrolyzed to galactose, mannose and mannobiose through the sequential actions of the purified galactosidase and mannanase from the same strain. The enzyme hydrolyzed melibiose and raffinose, but not lactose.

• Bulletin of the Korean Chemical Society
• /
• v.27 no.8
• /
• pp.1222-1224
• /
• 2006

• KSBB Journal
• /
• v.9 no.3
• /
• pp.312-318
• /
• 1994

The esterification of Ac-Tyr-OH was carried out in one-phase system containing ethanol by ${\alpha}$-chymotrypsin. The results of the esterification reaction are as follows. Chitin-${\alpha}$-chymotrypsin complex was found to be an effective catalyst for the esterlfication of Ac-Tyr-OH in ethanol organic solvent. The optimal conditions for the esterification were chitn/${\alpha}$-chymotrypsin ratio, 20(w/w); reaction temp., $35^{\circ}C$; reaction pH, 8.0; reaction time, 24 hrs. Also, addition of chitin in water/water-miscible organic solvent was effective for the stability of the enzyme. The esterification yield, Km and Vmax under optimal conditions were 93%, 3.093mM and 1.088mM/mg/hr, respectively.

• Journal of Industrial Technology
• /
• v.25 no.B
• /
• pp.229-239
• /
• 2005

Dietary powder from Plantaginis ovatae testa was prepared by mechnical milling/grinding of the outer layer of the seed. The crystalline/surface structures of its powder (100 mesh) were examined, and several physical functionalities including, water capacity, oil holding capacity, emulsion/foam properties and physiological functionality such as in-vitro glucose and bile acid retarding effects were also investigated. Water holding capacity(WHC) of psyllium powder was $33.71{\pm}0.10g$ water retained/g solid at room temperature, whileas oil holding capacity(OHC) for soybean or rice bran oil were about 1.80g oil retained/g solid. These values of WHC and OHC were about 5.6 times higher and 2.8 times lower than those of commercial ${\alpha}$-cellulose, respectively. Changes of pH showed a small effect on WHC, but WHC increased with temperature. Emulsion capacity of 2%(w/v) psyllium was about 60% level of 0.5%(w/v) xanthan gum but emulsion stability after incubation of 24 hours showed about 1.4 times improvement of xanthan gum(0.5%,w/v). Also, psylliume(above 2%, w/v) alone had higher foam capacity than that of xanthan(1.1 times) and especially, 1 or 2% addition of psyllium improved the foam stability of protein solution(1% albumin+0.5% $CaCl_2$) by factor of 3.3 and 6.0 times, respectively. The glucose and bile acid retarding effects of psyllium powder were relatively very excellent suggesting the prevention from diabetes and arteriosclerosis. Especially, psyllium showed the 3.7 and 3.3 times higher effect on in-vitro glucose and bile acid retardation than those of commercial ${\alpha}$-cellulose, respectively.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.3
• /
• pp.518-522
• /
• 2004

In this study we examined effects of a new dietary supplement on the lipid level and body weight. The efficacy of this weight-reduction supplement, based on natural ingredients consisting of Phaseolus vulgaris, Garcinia cambogia, and microstalline cellulose, was investigated by randomized, placebo-controlled double-blind study. The 36 subjects were assigned evenly into weight-reduction supplemented (Active) and placebo groups (Placebo). The supplement could reduce the absorption of different types of sugar from the gastro-intestinal tract. A significant difference in weight reduction was shown in the active group (3.5 kg). Body composition measurements indicated that about 34% of fat loss in the active group could be achieved. These findings suggest that this dietary supplement could reduce body weight and fat gains, and its inhibitory effects might lead to obesity improvement.

• Applied Biological Chemistry
• /
• v.33 no.1
• /
• pp.79-86
• /
• 1990

Cyclodextrin hydrolase from Bacillus stearothermophilus KFCC 21203 was purified and the properties of the purified enzyme were investigated. The enzyme was purified 15 folds with 77 % recovery by ammonium sulfate fractionation, DEAE-cellulose chromatography, and Ultro AcA 34 gel filtration. The specific activity and the molecular weight of the enzyme were 1.30 units/mg protein and about 29,500, respectively, The maximum activity of the enzyme was shown at $55^{\circ}C$ and pH 5.5. However, stable temperature and pH were $40^{\circ}C$ and $5.0{\sim}8.0$, respectively. The Km value for ${\gamma}-cyclodextrin$ was $3.78{\times}10^{-3}$ M. The degradation activity of the enzyme was selectively high for ${\gamma}-cyclodextrin$, and very low for ${\beta}-cyclodextrin$, but not for ${\alpha}-cyclodextrin$. The decomposed products of ${\gamma}-cyclodextrin$ were mainly glucose and maltose, and a little mlatotriose. The activity of the enzyme was very high for amylose, potato starch, corn starch, amylopectin and maltooligomer, and relatively high for glycogen and dextrin. The decomposed products of them were mainly glucose and maltose.

• Journal of the Korean Wood Science and Technology
• /
• v.46 no.4
• /
• pp.393-401
• /
• 2018

Natural fibers derived from lignocellulosic materials are considered to be more environment-friendly than petroleum-based synthetic fibers. Several natural fibers, such as seedpod fibers, have a potential for development, including kapok and balsa fibers. The characteristics of both fibers were evaluated to determine their suitability for specific valuable applications. The purpose of this study was to analyze some important fundamental properties of kapok and balsa fibers, including their dimensions, morphology, chemical components, and wettability. The results showed that the average fiber lengths for kapok and balsa were 1.63 and 1.30 cm, respectively. Kapok and balsa fibers had thin cell walls and large lumens filled with air. The kapok fiber was composed of 38.09% ${\alpha}-cellulose$, 14.09% lignin, and 2.34% wax content, whereas the balsa fiber was composed 44.62% ${\alpha}-cellulose$, 16.60% lignin, and 2.29% wax content. The characteristics of kapok and balsa fibers were examined by X-ray diffraction, Fourier-transform infrared spectroscopy and differential scanning calorimetry analyses. The contact angle of the distilled water on kapok and balsa fibers was more than $90^{\circ}$, indicating that both fibers are hydrophobic with low wettability properties because of to the presence of wax on the fiber surface.