• The Korean Journal of Mycology
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• v.18 no.1
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• pp.7-12
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• 1990

Isolates of Penicillium expansum with reduced pathogenicity were arbitrarily selected among benomyl-resistant isolates in order to investigate relationship of their pectolytic enzyme acitivity with pathogenicity. In artificial medium, strongly pathogenic isolate $S_1$ and weakly pathogenic isolate $R_2$ produced considerable amonts of endo-polymethylgalacturonase, endo-polygalacturonase, pectin methyl-trans-eliminase, and polygalacturonate-trans-eliminase. No marked difference in enzyme activities was observed between two isolates. In apple medium, the activities of endo-polymethylgalacturonase and endo-polygalacturonase of isolate $S_1$ were over 6 times higher than those of isolate $R_2$. But pectin methyl-trans-eliminase and polygalacturonate-trans-­eliminase did not show a great difference. Activities of endo-polymethylgalacturonase and endo­polygalacturonase precipitated at 80-95% saturation of ammonium sulfate were highest, and addition of these enzyme solutions increased pathogenicity of weakly pathogenic isolates $R_{1-4}$.

• The Korean Journal of Food And Nutrition
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• v.30 no.6
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• pp.1359-1363
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• 2017

The purpose of this study was that the optimal hydrolysis conditions of endo- and exo-type enzymes were selected to utilize organic cheese byproducts. Optimal substrate concentration and optimum enzyme ratio were measured by using 4 kinds of endo-type enzymes (alcalase, neutrase, protamex, and foodpro alkaline protease) and two exo-type enzymes (flavourzyme and prozyme 2000P) for whey protein hydrolysis were analyzed using liquid chromatography. As a result, the optimal endo-type enzyme through the first enzyme reaction was selected as alcalse, and as a result of the secondary enzyme reaction, flavourzme was selected as the Exo type enzyme. The concentration of whey protein substrate for optimal primary and secondary enzyme reactions was 10%. In addition, the optimum ratio of enzyme was 0.5% of alcalase and 0.2% of flavourzyme, which showed low molecular weight chromatography pattern compared to 2% of alcalase and 1% of flavourzyme hydrolyzate. Therefore, hydrolyzing the endo-type enzyme alcalase at a concentration of 0.5% for 10 hours and then hydrolyzing the exo-type enzyme flavouryme at a concentration of 0.2% for 4 hours was considered to be the optimum condition.

• Microbiology and Biotechnology Letters
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• v.20 no.1
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• pp.20-24
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• 1992

In order to reuse inulinase effectively, a method for immobilizing both endo- and exoinulinase to vinylsulfone activated agarose via covalent bond was investigated. The immobilized enzyme preparation had, respectively, 400 U for exoinulinase activity and 80 U for endoinu- Iinase activity per gram gel. A thermal stability by immobilization had increased in the case of exoinulinase. Optimum pHs for two immobilized enzymes were 4.4 to 5.0. Synergistic effect which depends on mixed ratio of two immobilized enzymes was the best when the mixed ratio of endo/exo lay between 0.1 and 0.5, and its activity of the mixed enzyme increased 1.7 times as compared to that of each immobilized enzyme. Inulinase activities of both of the immobilized enzymes did not change during 20 times experimental runs in a batch reactor.

• Applied Biological Chemistry
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• v.33 no.1
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• pp.73-78
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• 1990

Endo-polygalacturonase was purified from tomato, Lycopersicon esculentum L. The purification procedures included gel filtration on Sephadex G-150 and DEAE-cellulose ion exchange chromatography. Yield of the enzyme purification was 12.74 %. Purified enzyme was confirmed as a active single band by the SDS-polyacrylamide gel electrophoresis. When the purified enzyme was applied to SDS-PAGE, the molecular weight was estimated about 50,000. The optimum pH for the enzyme activity was 5.0 and the range of its stability to the pH was 4.0 to 5.0. The optimum temperature was $50^{\circ}C$, while the enzyme was abruptly inactivated above $50^{\circ}C$. From the result of the study on the effects of metals ion, it was found that $Ag^+$, $Zn^{++}$ and $Mg^{++}$ increased on the enzyme activity. In contrast, $Ba^{++}$, $Hg^{++}$, $Pb^{++}$, $Ca^{++}$, $Mn{++}$, $Cu^{++}$, $Fe^{+++}$, $Na^+$ and $K^+$ decreased it. the reaction catalyzed by this enzyme followed typical Michaelis-Menten kinetics with the Km value of $1.43{\times}10^{-1}\;mol/l$.

• Korean Journal of Microbiology
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• v.38 no.4
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• pp.241-246
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• 2002

A gene coding for endo-$\beta$-1,3-1,4-glucanase of Bacillus circulans was subcloned into Escherichia coli Ml5 using pQE30 as an expression vector. Endo-$\beta$-1,3-1,4-glucanase produced by the recombinant expression plas-mid pLQ43 was intactly purified to a single protein through a nickel-nitrilotriacetic acid (Ni-NTA) metal-affinity chromatography method. The molecular mass of the purified enzyme was estimated to be 28 kDa by SDS-PAGE. The optimum pH and temperature of the enzyme activity were pH 6.8 and $60^{\circ}C$, respectively. This enzyme was fairly stable in the pH ranging 5.5~7.5 and at the temperatures lower than $55^{\circ}C$. The enzyme appeared to be sensitive to most of the metal ions, especially to $Hg^{2＋$, and also to methanol, ethanol, isopropanol or 1-butanol at a concentration of 10%(v/v).

• Journal of the Korean Graphic Arts Communication Society
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• v.26 no.1
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• pp.17-28
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• 2008

The wood-pulp is treated with the three enzymes; Endo-xylanase, exo-xylanase and acetyl-esterase. The maximum value of relative activity appeared 0.95 in acetyl-esterase at $40^{\circ}C$, 0.9 in exo-xylanase at $40^{\circ}C$, and 0.8 in endo-xylanase at $50^{\circ}C$, respectively. And it has measured 0.8 in endo-xylanase, 0.95 in acetyl-esterase at pH 6 and 0.9 in exo-xylanase at pH 5, while the maximum value of relative activity does not rely on reaction time for three enzymes treatment, and the value was about 0.9, respectively. We have watched that decreased Kappa number and increased brightness. And it turned out that the three enzyme produced a lot of reducing sugar with wood-pulp treatment.

• Applied Biological Chemistry
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• v.37 no.4
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• pp.243-247
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• 1994

Endo-polygalacturonase was purified from Jujube. The purification procedures included DEAE-cellulose ion exchange chromatography and gel filtration on Sephdex G-100. Enzyme was purified as a single protein band and purification yield was about 6%. When the purified enzyme was applied to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the molecular weight was estimated about 19,000. Purified enzyme formed hexagonal board type.

• Korean Journal of Microbiology
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• v.25 no.2
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• pp.157-164
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• 1987

A new endo-$\beta$-1, 4-glucanase was purified from the culture filtrate of thermophilic anaerobic Clostridium thermocellum. The purification procedure included two steps of ion exchange chromatography with DEAD-Sephadex A-50 and gel filtration chromatography with Sephadex G-75. Even though the 56 fold increase in CMCase specific activity was obtained, the actually recovered enzyme activity was relatively lower level of 0.7%. Judging from the two bands in SDS-polyacrylamide gel electrophoresis, the endo-$\beta$-1, 4-glucanase consists of two subunits whose M.W. are 38,000 and 58,000, respectively. The optimum pH and temperature were determined to be 5.0 and $65^{\circ}C$, respectively. The enzyme was stable up to $70^{\circ}C$, but inactivated at $80^{\circ}C$. The kinetic parameters of the separated fraction were also determined. The purified enzyme did not show any significant hydrolytic activity against the highly ordered crystalline cellulose as well as filter paper.

• Journal of the Korean Graphic Arts Communication Society
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• v.26 no.1
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• pp.65-72
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• 2008

Kappa number and brightness were more increased with treatment of endo-xylanase than hydrogen-peroxide. In pulp bleaching process, endo-xylanse was most effective in the other enzyme treatment. Exo-xylanase was effective more than 4 unit treatment. Kappa number was tiny increased with enzyme ratio, but less than 4 unit treatment, increased with hydrogen peroxide treatment ratio. In more than 4 unit acetyl-estease treatment, Kappa number and brightness were not influenced with enzyme treatment ratio, but concentration of hydrogen-peroxide.

• Journal of Microbiology and Biotechnology
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• v.28 no.10
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• pp.1671-1682
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• 2018

Alginate lyases (endo and exo-lyases) are required for the degradation of alginate into its constituting monomers. Efficient bioethanol production and extraction of bioactives from brown algae requires intensive use of these enzymes. Nonetheless, there are few commercial alginate lyase preparations, and their costs make them unsuitable for large scale experiments. A recombinant expression protocol has been developed in this study for producing seven endo-lyases and three exo-lyases as soluble and highly active preparations. Saccharification of alginate using 21 different endo/exo-lyase combinations shows that there is complementary enzymatic activity between some of the endo/exo pairs. This is probably due to favorable matching of their substrate biases for the different glycosidic bonds in the alginate molecule. Therefore, selection of enzymes for the best saccharification results for a given biomass should be based on screens comprising both types of lyases. Additionally, different incubation temperatures, enzyme load ratios, and enzyme loading strategies were assessed using the best four enzyme combinations for treating Macrocystis pyrifera biomass. It was shown that $30^{\circ}C$ with a 1:3 endo/exo loading ratio was suitable for all four combinations. Moreover, simultaneous loading of endo-and exo-lyases at the beginning of the reaction allowed maximum alginate saccharification in half the time than when the exo-lyases were added sequentially.