• Journal of Applied Biological Chemistry
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• 제55권1호
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• pp.13-17
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• 2012

In order to enzymatically produce chitooligosaccharide using the crude enzyme preparation from Bacillus cereus D-11, we first studied the optimal reaction conditions. It was found that the optimal temperature for hydrolysis of chitosan was $55^{\circ}C$. The ratio of enzyme/substrate should not be lower than 0.13 U/mg in the reaction mixture. The enzyme activity was stable below $50^{\circ}C$. The products of enzymatic reaction were analyzed by both thin layer chromatography and high performance liquid chromatography. Under the appropriate condition, chitosan was hydrolyzed using the enzyme preparation. The resulting chitooligosaccharides were purified and separated by Dowex ($H^+$) ion exchange chromatography. From 4 g soluble chitosan, 0.95 g $(GlcN)_2$, 1.43 g $(GlcN)_3$, and 1.18 g $(GlcN)_4$ were recovered.

• 동아시아식생활학회지
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• 제4권3호
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• pp.87-96
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• 1994

This study was carried out to investigate the effect of hydrolysis by proteolytic enzymes on the functional properties of sesame protein concentrate. Sesame protein concentrate was hydrolyzed with papain, pepsin and trypsin to obtain 10% and 20% degree of hydrolysis. The nirogen solubility in water was increased with increasing the degree of hydrolysis. Bulk density was increased by enzymatic hydrolysis but water absorption capacity was increased only in the case of pepsin-hydrolyzed SPC. Higher fat absorption capacity was found in SPC with 10% DH than SPC with 20% DH. Emulsifying activity was also increased by enzymatic hydrolysis except SPC with 10% DH by papain.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1978년도 추계학술대회
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• pp.208.2-208
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• 1978

Rice Straw was delignified by autoclaving with 1％ NaOH solution at $121^{\circ}C$ for one hour and was disintegrated by a Wiley mill to 60 mesh. This substrate was saccharified with cellulase produced by Trichoderma viride T04 in solid culture me-dium. The rate and extent of hydrolysis were both increased when high enzyme concentration and low substrate concentration were employed. The original cellulose was treated with 0.19 FPA unit for three hours and followed by the second treatment for the same period with the same concentration of enzyme after washing. By doing this the hydrolysis rate at the second stage could increase four folds of that unwashed. The same experiment with 0.32 FPA unit yielded two folds suggesting an end-product inhibition on the recaction system. The extent of hydrolysis however, could not be in-creased by this process.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권6호
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• pp.367-370
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• 2002

Candida cylindracea lipase was immobilized by adsorption on acid washed glass beads. It was observed that protein loading of the support depends on the size of the particle, with smaller particle containing higher amount of protein per unit weight. Initial reaction rate linearly varied up to enzyme concentration of 17.25 U/mL. Amount of free fatty acids produced was linearly proportional up to the enzyme loading of 1650 $\mu$g/g of bead. Achievement of chemical equilibrium took longer time in the case of less protein loading. Degree of hydrolysis was found to decrease in second and third consecutive batch operations on repeated use of immobilized lipase.

• Preventive Nutrition and Food Science
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• 제5권4호
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• pp.179-183
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• 2000

$\beta$-1,4-Mannotriose was prepared b he enzymatic hydrolysis of white copra meal (WCM) and the subsequent elimination of monosaccharides from the resultant hydrolysate with a yeast. The enzyme system from sunflower seed hydrolyzed WCM and produced monosaccharides and $\beta$-1,4-mannotriose without other oligomers at the final stage of the reaction. WCM(50g) was hydrolyzed at 5$0^{\circ}C$ and pH 4.5 for 24 hr with crude enzyme solution (500 mL) from sunflower seed. By the elimination of monosaccharides from the hydrolysis products with a yeast (Candida glaebosa), 8.1 g of crystalline mannotriose was obtained without the use of chromatographic techniques. After 48hr of yeast cultivation, the total sugar content decreased from 4.6% to 3.5%, whereas the average degree of polymerization increased from 2.3 to 3.1.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.951-956
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• 2001

A 28-kDa extracellular lipase (pI 8.7) was purified to homogeneity from the culture supernatant of Trichosporon sp. Y- 11 by mmonium sulfate precipitation, DEAE-Sephadex A-50, Bio-Gel P-30, CM- Sephadex C-50, and Bio-Gel P- 10 chromatographies. The purified enzyme exhibited a specific activity of $2,741{\;}{\mu}mol/min/mg$ based on the hydrolysis of triolein, and the optimal hydrolysis activity was dentified at pH 8.0 and $40^{\circ}C$. The enzyme activity was inhibited by $Ag^+$ and enhanced by $Fe^{2+}$, $Fe^{3+}$, $Mg^{2+}$, $Mn^{2+}$, and $Li^{+}$. The enzyme activity exhibited for the hydrolysis of both tributyrin and trilinolein. The ester synthesis of unsaturated fatty acids with various alcohols catalyzed by the purified lipase in a nonaqueous medium or microaqueous system was also investigated. The esterification activity of the lipase increased with an increase of the carbon chain length in the alcohol. The synthesis rate of linoleic acid and oleyl alcohol was the highest with an optimal temperature and pH of $40^{\circ}C$ and 8.0, respectively. The water content and agitation also affected the esterification activity of the lipase.

• Journal of Applied Biological Chemistry
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• 제49권4호
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• pp.135-139
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• 2006

A alkalophilic strain, Bacillus licheniformis MH31 producing an alkaline protease was isolated from mine soil of Boryeong in Korea. Production of a high level of alkaline protease was achieved 42 h after incubation when the bacterium was grown at pH 9.0 and $35^{\circ}C$ in Horikoshi medium supplemented with 0.5%(w/v) starch and 1%(w/v) skim milk as carbon and nitrogen source, respectively. The molecular weight of partially purified enzyme was estimated to be 30 kDa by SDS-PAGE and its optimum pH was pH 10. The enzyme showed optimum temperature at $50^{\circ}C$, and was stable up to $60^{\circ}C$ after 1 h incubation. The protease was strongly inhibited by 1 mM of PMSF which was known well as strong inhibitor of serine proteases, but almost not inhibited by 5 mM of EDTA and 1,10-phenanthroline. When the protein hydrolysis products of 1% skim milk by partially purified protease was compared with available commercial proteases using HPLC analysis, most of hydrolysis products were detected below molecular weight of 10,000 and the hydrolysis ratio of purified enzyme was 24.8% lower than those(above 32%) of commercial proteases.

• 한국의류학회지
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• 제28권8호
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• pp.1048-1056
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• 2004

Hydrophilicities of finished cotton fabrics were evaluated in respect of moisture regain and wickability. Changes in internal structure were determined using X-ray diffraction and surface changes in degraded samples were observed through a microscopy. Activated sludge test, soil burial test and enzyme hydrolysis were employed to evaluate the biodegradabilities. In addition, correlation analysis was done between biodegradability and the factors affecting biodegradability in each evalution methods. It was shown that hydrophilicities of silicone finished specimens were lower than that of untreated cotton and decreased in a row of PDMS(polydimethyl siloxane : -CH$_3$)＞AFS(amino functional siloxane ; -C$_3$H$_{6}$ NHC$_2$H$_4$NH$_2$)＞MHPS(methylhydrogen polysiloxane : -H, Cat : (C$_{17}$ H$_{35}$ COO)$_2$Zn) Although, moisture regain of mercerized cotton was higher than those of the others, wickability was shown to be lower. It was represented that crystalinities of cotton fabrics decreased by the silicone treatment. In activated sludge test and soil burial test, biodegradabilities of silicone treated specimens were lower than that of untreated cotton, where specimens of higher biodegradability exhibited higher biodegradability except mercerized ones. The results from enzyme hydrolysis, however, showed somewhat different tendency in that biodegradability was more closely related with the crystallinities of fabrics. It can be thought that enzyme hydrolysis is carried out for short time, physical accessibility becomes important.

• Applied Biological Chemistry
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• 제38권3호
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• pp.248-253
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• 1995

참깨박 단백질의 기능개선을 위한 가수분해 조건을 검토한 결과 분리된 참깨박단백질에 대한 각 효소의 최적작용조건은 papain의 경우 pH 6.0, $60^{\circ}C$,효소 대 기질의 비는 기질량에 대해 3%, 기질농도 1.5%에서 최적이었으며, pepsin은 pH 2.0, $50{\sim}60^{\circ}C$, 효소의 농도는 기질량에 대해 3%, 기질농도 1%에서 최적이었다. 그리고 trypsin은 pH 9.0, $60^{\circ}C$, 효소의 농도는 기질량에 대해 1%, 기질의 농도 1%에서 가장 높은 효소작용을 보였다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.485-489
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• 2003

Enzymatic hydrolysis of egg yolk Protein was carried out in continuous packed column reactor Five supports for enzyme immobilization were evaluated in this study. We investigated the optimum operation variables - pH, temperature, and flow rate in continuous reactor operation.