• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1143-1147
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• 1998

Enzymatic characterization of peroxidase(E.C. 1.11.1.7) from soybean sprouts was investigated. The optimum pH of the purified peroxidase was 7.0 and relatively stable at pH 6.0~7.0. And the optimum temperature was 50oC. The enzyme was most active with guaiacol as a substrate, followed by (＋)catechin, pyrogallol and p phenylenediamine. The Km values for guaiacol and H2O2 were 4.2mM and 2.5mM, respectively. L Ascorbic acid and 2 mercaptoethanol greatly inhibited the enzyme activity, while Cu2+, Co2+ and Ni2+ activated the enzyme.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.11 no.4
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• pp.205-211
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• 1978

The effect of phenol derivatives (guaiacol, vanillin, o-vanillin, eugenol) and catechol derivatives (pyrogallol, resoicinol) to enhance the volumetric oxygen transfer coefficient, in the aerobic fermentation was studies. Guaiacol, vanillin, o-vanillin, pyrogallol and resorcinol revealed to enchance the volumetric oxygen transfer coefficient, and eugenol had no such ability. The enhancement of the oxygen transfer ability is probably due to the formation of the charge transfer complex by the derivatives and oxygen molecules.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.2
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• pp.96-99
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• 2006

In this study, we have attempted to determine the optimum concentration of inducers responsible for efficient laccase production by the white-rot fungus, Trametes sp. Variations in laccase activity were investigated with changing concentrations of 2,5-xylidine, syringaldazine, ABTS, and guaiacol. Enhancement of peak laccase activity was achieved via the combination of 2,5-xylidine with ABTS, syringaldazine, or guaiacol, resulting in increases of up to 359, 313, and 340%, respectively, as compared to control values. Among the tested inducers, the addition of 0.1mM of ABTS coupled with 1.0mM of 2,5-xylidine in the medium after 24 h of cultivation proved optimal with regard to laccase enzyme production.

• BMB Reports
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• v.31 no.6
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• pp.548-553
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• 1998

A minor anionic isoperoxidase named $A_{3n}$, was isolated from Korean radish (Raphanus sativus L.) root. Purification of the enzyme was accomplished by CMcellulose chromatography, DEAE-Sephacel chromatography, and Sephadex G-75 gel filtration. The enzyme was a glycoprotein with molecular weight of approximately 31,000 as determined by SDS-PAGE and 33,000 by Sepadex G-150 gel filtration, which is by far the smallest among the reported isoperoxidases. The pI value was 3.5. The optimum pH of the enzyme was 6.5 for guaiacol and $H_2O_2$, and the $K_m$ values for guaiacol and $H_2O_2$ were 13.3 mM and 1.5 mM, respectively. Kinetic studies with various substrates revealed that only A3n, unlike other isoperoxidases from radish, did not use scopoletin as a substrate and had very low $K_m$ value of 0.25 mM for ferolic acid among naturally occurring phenolic substrates.

• Journal of Microbiology and Biotechnology
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• v.23 no.6
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• pp.864-871
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• 2013

The recombinant strain P. pastoris GS115-lccC was used to produce laccase with high activity. Factors influencing laccase expression, such as pH, methanol concentration, copper concentration, peptone concentration, shaker rotate speed, and medium volume were investigated. Under the optimal conditions, laccase activity reached 12,344 U/L on day 15. The recombinant enzyme was purified by precipitating and dialyzing to electrophoretic homogeneity, and was estimated to have a molecular mass of about 58 kDa. When guaiacol was the substrate, the laccase showed the highest activity at pH 5.0 and was stable when the pH was 4.5~6.0. The optimal temperature for the laccase to oxidize guaiacol was $60^{\circ}C$, but it was not stable at high temperature. The enzyme could remain stable at $30^{\circ}C$ for 5 days. The recombinant laccase was used to degrade chlorpyrifos in several laccase/mediator systems. Among three synthetic mediators (ABTS, HBT, VA) and three natural mediators (vanillin, 2,6-DMP, and guaiacol), vanillin showed the most enhancement on degradation of chlorpyrifos. Both laccase and vanillin were responsible for the degradation of chlorpyrifos. A higher dosage of vanillin may promote a higher level of degradation of chlorpyrifos, and the 2-step addition of vanillin led to 98% chlorpyrifos degradation. The degradation of chlorpyrifos was faster in the L/V system ($k_{obs}$ = 0.151) than that in the buffer solution ($k_{obs}$ = 0.028).

• Horticultural Science & Technology
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• v.18 no.6
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• pp.783-786
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• 2000

This study was carried out to examine the effect of root-zone temperatures on seedling growth, mineral contents and antioxidative enzyme activities of grafted watermelon. The grafted watermelon seedlings were grown in greenhouse bed for 20 days at root-zone day temperatures of 10, 15, $25^{\circ}C$ while night temperature was maintained at $10^{\circ}C$. Growth such as shoot height, leaf length, leaf number, stem diameter, and fresh and dry weights increased as increasing root-zone temperatures, and leaf area with $25^{\circ}C$($52.79mm^2$) was two times that of control($21.50mm^2$). As increasing the root-zone temperatures, Mn, Ca, Fe contents increased, K, P, Mg were non significant, and Na decreased. The activities of ascorbate peroxidase(APX) and guaiacol peroxidase(GPX) known as antioxidative enzyme were higher at $10^{\circ}C$ than $25^{\circ}C$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.4
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• pp.416-423
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• 2013

Germination is controlled by internal factors of seeds and external factors such as water, temperature and light. We investigated the relationship between germination characteristics of four waxy rice cultivars and patterns of water uptake, antioxidant enzymes and free soluble sugars during early imbibition. Seed viabilities by tetrazolium test of four different rice cultivars were higher than 95% and germination rates of the hulled rice seeds were on 95% average. However, germination rate of intact rice among four cultivars showed a big difference depending on temperature. Water uptake of hulled and intact rice seeds during imbibition reached a stationary phase at around 30% moisture content. Although rates of water uptake were faster in hulled rice and high temperature than intact rice and low temperature condition, difference of those among cultivars was greater under low temperature than high temperature. The time required for rice seeds to uptake 30% water was negatively correlated with percentage of germination, germination energy, germination speed and mean germination time. Guaiacol peroxidase activity at 24h of imbibition was correlated with germination energy and germination speed but not percentage of germination. Catalase activity, soluble protein and maltose concentration at 24h of imbibition were not correlated with characteristics of germination. These results suggest that a time required for rice seeds to uptake 30% of water significantly correlated with germination and guaiacol peroxidase activity during early imbibition plays an important role in initiation of germination.

• Applied Biological Chemistry
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• v.43 no.2
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• pp.100-105
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• 2000

Anionic peroxidases (POD) were isolated from Korean radish (Raphanus sativus L.) root by using fractionation with $(NH_4)_2SO_4$ and CM-cellulose ion exchange chromatography and used as the colorimetric enzyme for glucose determination. The chromogen used in this work was o-tolidine or 4-aminoantipyrine/diethylaniline (4AA/DEA) and the colored products were measured at 630 nm. Korean radish anionic POD showed much better colorimetric reaction of glucose determination with 4AA/DEA than with o-tolidine. The r values of calibration curve for glucose determination by o-tolidine and 4AA/DEA were 0.9983 and 0.9963, respectively. In order to compare the reactivity for substrate oxidation by Korean radish POD and horseradish POD, the Km values against o-dianisidine and guaiacol were measured. Korean radish POD had about 40 fold higher affinity for o-dianisidine and 2 fold higher affinity for guaiacol as revealed by Km values. These results showed that Korean radish POD could be developed as the colorimetric diagnosis reagent for glucose determination with high sensitivity.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.80-86
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• 2002

Volatile compounds in three different kinds of crude vinegars obtained from oak (Quercus serrata), bamboo (phyllostachys) and pine (Pinus densiflora) species were analyzed by the solid-phase microextraction (SPME) method. A total of 264 peaks were detected on the chromatograms obtained from the polar (CBP 20) and the nonpolar (CBP 1) columns, which were used for analyzing the volatile compounds in these vinegars. The major volatile compounds identified by using the polar column were 2-butanone, acetic acid, guaiacol, phenol, cresols, 4-ethyl guaiacol, 4-ethyl phenol, and syringol. Using the nonpolar column, seven compounds could be identified: 1,2-dimethoxybenzyl alcohol, 1-hydroxy-2-butanone, 1-(2-furanyl)-1-propane, ethisolide, furfuryl acetate, 1,2-dimethoxybenzene, phenyl acetate. The volatile compounds were classified into five groups: phenols, neutral compounds, organic acids, esters and others. The phenols were the main component and comprised 49~65% of the volatile compounds of these vinegars. In the case of bamboo vinegar, the proportion of the phenols in the volatile compounds was lower than that of the two wood vinegars. However, the proportions of the neutral compounds and the organic acids were higher than those of the wood vinegars. Therefore, it seems that these differences of the proportions of the volatile compounds would make a certain difference of a smoke flavor between the bamboo vinegar and the wood vinegars.

• BMB Reports
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• v.33 no.4
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• pp.312-316
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• 2000

Effects of various nitrogenous compounds on the peroxidative activity of Korean radish (Rophanus sativus L.) isoperoxidase $A_1$ were examined by using anilino substrates, such as dianisidine and phenylenediamine. We also used phenolic substrates such as guaiacol, chlorogenic acid, caffeic acid, ferulic acid and esculetin. The peroxidation of dianisidine was stimulated by adenine and imidazole as much as 5 fold and 11 fold, respectively at pH 8. Moreover, about 4.8 fold and 8 fold stimulation of phenylenediamine peroxidation occurred by adenine and imidazole, respectively at pH 8. The stimulation by adenine and imidazole did not occur at the acidic pH range. The peroxidations of phenolic substrates, such as guaiacol, chlorogenic acid, caffeic acid, ferulic acid and esculetin, were not boosted greatly by any of the nitrogenous compounds tested. Notably, ammonium salt, which has been known for the excellent booster of horseradish peroxidase, did not affect the peroxidation of the Korean radish isoperoxidase $A_1$. The kinetic studies of dianisidine peroxidation with imidazole, as a model of boosting reaction, showed that neither the affinity of imidazole against dianisidine, nor the activation energy of dianisidine peroxidation changed during the activity boosting of isoperoxidase $A_1$.