• Journal of Periodontal and Implant Science
• /
• v.32 no.3
• /
• pp.665-683
• /
• 2002

A novel glucanhydrolase from a mutant of Lipomyces starkeyi KSM 22 has additional amylase activity besides mutanolytic activity and has been suggested as promising anti-plaque agent. It has been shown effective in hydrolysis of mutan, reduction of mutan formation by Streptococcus mutans and removal pre-formed sucrose-dependent adherent microbial film and has been strongly bound to hydroxyapatitie. These in vitro properties of Lipomyces starkeyi KSM 22 glucanhydrolase are desirable for its application as a dental plaque control agent. In human experimental gingivitis　model and 6 month clinical trial, mouthrinsing with Lipomyces　starkeyi KSM 22 dextranase was comparable to 0.12% chlorhexidine mouthwash in inhibition of plaque accumulation and gingival inflammation and local side effect was negligible. This study was aimed to evaluate the cytotoxic effect of Lipomyces starkeyi KSM 22 glucanhydrolase on human gingival fibroblasts. Primary culture of human gingival fibroblasts at the 4th to 6th passages were used. Glucanhydrolase solution was made from lyophilized glucanhydrolase powder from a mutant of Lipomyces stakeyi KSM 22 solved in PBS and added to DMEM medium to the final concentration of 0.5, 1, and 2 unit. Cells were exposed to glucanhydrolase solution or 0.1 % chlorhexidine and the cells cultured in DMEM with 10% FBS and 1% antibiotics as control. After exposure, the morphological change, cell attachment, and cell activity by MTT assay were evaluated in 0.5, 1.5, 3, 6, 24 hours after treatment. The cell proliferation and cell activity was also evaluated at 2 and 7 days after 1 minute exposure, twice a day. The cell morphology was similar between the Lipomyces smkeyi KSM 22 glucanhydrolase groups and control group during the incubation periods, while most fibroblasts remained as round cell regardless of incubation time in the chlorhexidine group. The numbers of the attached cells in the glucanhydrolase groups were comparable to that of control and significantly higher than the chlorhexidine group. The numbers of the proliferated cells in the glucanhydrolase groups at 7 days of incubation were comparable to the control group and higher than the chlorhexidine group. The cell activity in glucanhydrolase groups paralleled with the increased cell number by attachment and proliferation. According to these results, Lipomyces starkeyj KSM 22 glucanhydrolase has little harmful effect on attachment and proliferation of human gingival fibroblasts, in contrast to 0.1% chlorhexidine which was cytotoxic to human gingival fibroblasts. Therefore this glucanhydrolase preparation is considered as a safe and promising agent for new mouthwash formula in the near future.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.6
• /
• pp.794-801
• /
• 2013

This paper reports the production and characterization of crude xylanase from the newly isolated Humicola sp. Ly01. The highest (41.8 U/ml) production of the crude xylanase was obtained under the optimized conditions (w/v): 0.5% wheat bran, 0.2% $KH_2PO_4$, and 0.5% peptone; initial pH 7.0; incubation time 72 h; $30^{\circ}C$; and 150 rpm. A considerable amount of the crude xylanase was induced using hulless barley bran or soybean meal as the carbon source, but a small amount of the enzyme was produced when supplementary urea was used as the nitrogen source to wheat bran. The crude xylanase showed apparent optimal cellulase-free xylanase activity at $60^{\circ}C$ and pH 6.0, more than 71.8% of the maximum xylanase activity in 3.0-30.0% (v/v) ethanol and more than 82.3% of the initial xylanase activity after incubation in 3.0-30.0% (v/v) ethanol at $30^{\circ}C$ for 2 h. The crude xylanase was moderately resistant to both acid and neutral protease digestion, and released 7.9 and 10.9 ${\mu}mol/ml$ reducing sugar from xylan in the simulated gastric and intestinal fluids, respectively. The xylooligosaccharides were the main products of the hydrolysis of xylan by the crude xylanase. These properties suggested the potential of the crude enzyme for being applied in the animal feed industry, xylooligosaccharides production, and high-alcohol conditions such as ethanol production and brewing.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2011.10a
• /
• pp.167-177
• /
• 2011

Renewable energy resources and technologies have the potential to provide long-lasting solutions of the global energy-requirements faced by the economic and environmental sectors of a nation. Therefore, waste money bills were used as renewable energy source for the production of bio-ethanol. In this study, different concentrated NaOH 0.5%. 1.0%, 2.0%, 3.0% and 0.0% (as a control) were used for 10, 20 and 30 mins at $121^{\circ}C$/15 psi in an autoclave. Saccharification and fermentation (aerobic and anaerobic) were carried out through commercial enzyme Celluclast 1.5 L, Novozymes 188 and Saccharomyces cerevisiae KCCM 11304 respectively. The results of pretreatment showed that the NaOH pre-treated substrate enhanced enzyme action and released more amount of glucose. The amount of glucose was found with the increasing concentration of NaOH and time $44996.95{\pm}6.30$, $46763.10{\pm}3.56$, $53421.32{\pm}4.72$, $63431.25{\pm}6.95$ and $56850.98{\pm}6.75\;ng/{\mu}l$ for 30 min respectively. As for bioethanol, the conversion rate of NaOH resulted $1010.08{\pm}4.71$, $1050.25{\pm}4.37$, $1109.49{\pm}4.39$, $1139.25{\pm}3.26$ and $1020.77{\pm}3.89$ ppm for aerobic; $16730.54{\pm}6.67$, $17076.45{\pm}6.25$, $17516.17{\pm}4.49$, $19782.68{\pm}6.19$ and $17973.39{\pm}7.50$ ppm for anaerobic and $18935.02{\pm}4.59$, $19895.45{\pm}5.39$, $21912.95{\pm}4.83$, $24895.21{\pm}6.72$ and $18961.21{\pm}4.90$ ppm for anaerobic condition with benzoic acid for respective condition. Thus, the results of the present work clearly revealed that with the increasing of alkali concentration might be more effective for bio-ethanol production from waste money bill, which is economic and environmental friendly.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.23 no.5
• /
• pp.361-372
• /
• 1990

Processing conditions of whole sardine into modified fish sauce were investigated. Thawed and chopped sardine was homogenized and hydrolyzed using commercial proteolytic enzymes such as complex enzyme-2000($2.18{\cdot}10^4U/g solid$) and alcalase($1.94{\cdot}10^4\;U/g solid$) in a cylindrical vessel with 4 baffles and 6-bladed impeller. Optimal pH, enzyme concentration and temperature for the hydrolysis with complex enzyme-2000 were 7.0, $7\%$ (W/W) and $52^{\circ}C$, and-those with alcalase were 8.0, $6\%$ (W/W) and $60^{\circ}C$. In both cases, the reasonable amount of water for homogenization, agitation speed and hydrolyzing time were $100\%$ (W/W), 100 rpm and 210 minutes. Thermal treatment of the filtered hydrolysate at $90^{\circ}C$ for 2 hours with $6\%$ of invert sugar was adequated to inactivation of the enzymes and pasteurization of the hydrolysate. Flavor, taste and color of the hydrolysate were improved during the heating process in which the browning products might participate. The content of free amino nitrogen in the fish sauce seasoned with $15\%$ of table salt was ca. $1,640 mg\%$. Yield of the fish sauce based on the contents of proteinous and free amino nitrogen in the raw whole sardine was ca. $86\%$, and ca. $96\%$ of these compounds of the fish sauce was in the form of free amino nitrogen. The pH, salinity and histamine content of the fish sauce were $6.1\~6.3,\;14.2\~14.3\%$ and less than $10\;mg\%$.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.33 no.4
• /
• pp.325-330
• /
• 2000

Alginate obtained from brown algae had various physicochemical and rheological properties and could used as a dietary fiber, However, alginate has not been widely applied to the food industry, since it had high viscosity, high gelling effect conjugated with some mineral, and low solubility. To improve functionality of alginate, partially develymerized alginates, which was water-soluble dietary fiber were obtained by hydrolysis of alginate from the sea tangle, Laminaria japonicus, heated at $121^{\circ}C$. Effects of depolymerization of alginate on the changes of viscosity and average molecular weight, block composition ratio of mannuronate to guluronate (M/G ratio), chemical properties using $PT-IR, ^1H-NMR, and ^(13)C-NMR$ spectrum were investigated. The average molecular weight and viscosity of the alginate were rapidly decreased with the thermal decomposition, and estimated to be 1,307,415 dalton and 284,000 cps, before heating, 728,106 and 3,940.29 cps after 30 min heating, 102,635 and 22.22 cps after 2.5 hrs heating, 51,205 and 12.05 cps after 3 hrs, and 10,049 and 4.28 cps after 6.5 hrs, respectively. The M/G ratio was increased with the heating time, while MM-block did not show any changes and GG-block diminished. The results of $FT-IR, ^1H-NMR and ^(13)C-NMR$ spectrum suggested that changes of molecular structure did not occur by the thermal decomposition.

• Journal of Life Science
• /
• v.18 no.1
• /
• pp.52-57
• /
• 2008

Xylan is a major hemicellulose component of the cell walls of monocots and hardwood, representing up to 30% of the dry weight of these plants. To efficiently hydrolyze xylan, the endoxylanase gene from Bacillus sp. was expressed in B. subtilis DB431 by introducing the plasmid pJHKJ4. The total activity of the recombinant endoxylanase reached about 857 unit/ml by batch fermentation of B. subtilis DB431/pJHKJ4 in LB maltose medium. The majority (>92%) of endoxylanase was efficiently secreted into the culture medium. The recombinant endoxylanase hydrolyzed more the birchwood xylan efficiently than the other xylans. When 4 % concentration of xylan was used, the highest production of xylooligosaccharide was observed, and xylobiose and xylotriose were the major products. Optimal amount of enzyme and reaction time for producing xylooligosaccharide were found to be 10 unit and 1 hr, respectively. In addition, the temperature of $40^{\circ}C{\sim}50^{\circ}C$ gave the highest production of xylooligosaccharide. Consequently, the optimized conditions for the production of xylooligosaccharide through the hydrolysis of xylan were determined as follows: 10 unit endoxylanase, $50^{\circ}C$, 4% birchwood xylan, 1 hr reaction.

• Korean Journal of Food Science and Technology
• /
• v.33 no.6
• /
• pp.784-788
• /
• 2001

Reliable data on the exposure of capsaicin, which evokes hot sensation in hot red pepper, are important prerequisites for studying biological functions of capsaicin in human body since its roles are controversial according to animal and epidemiological studies. To get accurate data, the use of urinary biomarkers was considered as a measure of internal exposure of capsaicin. After 2-day-capsaicin depletion five to six women in their 20's were instructed to eat 60 or 80 g/day hot red pepper soybean paste as a capsaicin source with meal which did not contain capsaicinoid, and to collect their urine separately. HPLC conditions were set to detect capsaicinoid and urinary metabolites at the same time. Most of capsaicinoid were excreted in the form of 4-hydroxy-3-methoxybenzoic acid in three subjects at the highest dose. This result suggests the oxidation of the 4-hydroxy3-methoxybenzaldehyde, the hydrolysis product of capsaicin, is the major metabolic pathway in the human body, whereas the reduction of the aldehyde is the major route in rats. However, neither any metabolite nor the parent compound was ever shown in two of the subjects reflecting large individual differences of capsaicin absorption and/or biotransformation.

• Applied Biological Chemistry
• /
• v.50 no.2
• /
• pp.87-94
• /
• 2007

A bacterium which has high enzymatic activities such as amylase, cellulase and protease was isolated from Korean traditional soybean food, doenjang. The isolated bacterium was identified to Bacillus subtilis HS25 by the test of morphological and biochemical properties according to Bergey's Manual of Systematic Bacteriology and API 50 CHL kit, and by the 16S rDNA sequence. The isolated B. subtilis HS25 had a potent antibacterial activity against food born causative or pathogenic bacteria. B. subtilis HS25 is endospore forming cell and contained flagella and abundant viscous material at the out layer of cell wall. It was rod type bacterium $(0.5{\sim}0.8{\times}3{\sim}5{\mu}m)$ having biochemical characteristics such as gram staining(+), catalase(+), oxidase(-) and hydrolysis of esculin(+). The optimal medium compositions for production of antibacterial substance in the B. subtilis HS25 were 1% of soluble starch, 0.5% of yeast extract, 0.5% of peptone and 0.05% of MgCl$_2{\cdot}6H_{2}O$. The optimum temperature and pH of the growth of the B. subtilis HS25 was 35$^{\circ}C$ and pH 7.5, respectively. The antibacterial activity was more high in neutral to a little alkaline pH (6.5-10.5) than in acidic pH. The optimal shaking speed to grow and to produce antibacterial substance of the B. subtilis HS25 was 160${\sim}$200 rpm. The optimal culture time for antibacterial activities of the bacterium were shown to be in the range of 12-36 hr.

• The Korean Journal of Pesticide Science
• /
• v.11 no.2
• /
• pp.87-94
• /
• 2007

Pyrethroid insecticide have widely been used for agricultural sector and residential environments. To assess the exposure of insecticide which is absorbed through skin the analysis of urinary metabolite is essential. At present, the urinary 3-PBA was analyzed using liquid-phase extraction. But LPE have many limitations, such as long pre-treatment time and low recovery. So, this study was conducted to determine the optimum conditions for analysing 3-PBA in urine using solid phase extraction. Furthermore, this study intend to investigate the relation of concentrations of pyrethroid, deltamethrin in air and 3-PBA in urine. The optimum condition for hydrolysis was found to be done with hydrochloric acid for one hour. The recovery rates of 3-PBA were $84.6%{\pm}1.2%$, $54.8{\pm}0.9%$, $99.8{\pm}1.2%$ with XAD-2, XAD-7, XAD-16 using as the aborbents and acetone as eluents respectively. But acetonitrle and methanol gave low recovery rate and methyl cellosolve could not elute the compound. The amount of acetone for elution were 6mL, 9mL, 3mL for XAD-2, XAD-7, XAD-16 as absorbents respectively. The non-absorbed rates was $0.8{\pm}0.5%$, and $0.7{\pm}0.3%$ under XAD-16, mesh size 140-200, amount of resin 1.4g and the flow rate of eluent was 0.1mL/min. In the concentration process, we obtained 11 times higher concentration of material. The amounts of urinary 3-PBA were. The LODs of 3-PBA and deltamethrin were 0.004 mg/L, 0.038 mg/L, respectively. The further research of minute monitoring which include spray pattern, environmental condition is needed And more research about the relation between total pyrethroid exposure and urinary various metabolite are also necessary.

• Journal of Ginseng Research
• /
• v.41 no.4
• /
• pp.572-577
• /
• 2017

Background: Panax ginseng Meyer is cultivated because of its medicinal effects on the immune system, blood pressure, and cancer. Major ginsenosides in fresh ginseng are converted to minor ginsenosides by structural changes such as hydrolysis and dehydration. The transformed ginsenosides are generally more bioavailable and bioactive than the primary ginsenosides. Therefore, in this study, hydrothermal processing was applied to ginseng preparation to increase the yields of the transformed ginsenosides, such as 20(S)-Rg3, Rk1, and Rg5, and enhance antioxidant activities in an effective way. Methods: Ginseng extract was hydrothermally processed using batch reactors at $100-160^{\circ}C$ with differing reaction times. Quantitative analysis of the ginsenoside yields was performed using HPLC, and the antioxidant activity was qualitatively analyzed by evaluating 2,2'-azino-bis radical cation scavenging, 2,2-diphenyl-1-picrylhydrazyl radical scavenging, and phenolic antioxidants. Red ginseng and sun ginseng were prepared by conventional steaming as the control group. Results: Unlike steaming, the hydrothermal process was performed under homogeneous conditions. Chemical reaction, heat transfer, and mass transfer are generally more efficient in homogeneous reactions. Therefore, maximum yields for the hydrothermal process were 2.5-25 times higher than those for steaming, and the antioxidant activities showed 1.6-4-fold increases for the hydrothermal process. Moreover, the reaction time was decreased from 3 h to 15-35 min using hydrothermal processing. Conclusion: Therefore, hydrothermal processing offers significant improvements over the conventional steaming process. In particular, at temperatures over $140^{\circ}C$, high yields of the transformed ginsenosides and increased antioxidant activities were obtained in tens of minutes.