• Korean Journal of Microbiology
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• v.49 no.4
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• pp.309-312
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• 2013

Fungal cell walls consist of various glucans and chitin. Fungi produce chitinases for their growth and development. The inky cap, Coprinellus congregatus, produces at least two different chitinases during its life cycle. Chitinase 1 (chi1) is expresses throughout its life cycle while chitinase 2 (chi2) is expressed at the mushroom autolysing phase. The cloned cDNA of chi1 is successfully expressed as a fusion protein with c-myc in Pichia pastoris, and purified by the affinity chromatography. The optimum pH and temperature of Chi1 was pH 8.0 and $35^{\circ}C$, respectively when 4-nitrophenyl N,N',N"-triacetyl-${\beta}$-D-chitotrioside was used as the substrate. The $K_m$ value and $V_{max}$ for the substrate was 0.780 mM and 0.10 OD $min^{-1}unit^{-1}$, respectively. The addition of purified Chi1 resulted in total growth inhibition against several plant pathogenic fungi such as Alternaria alternata, Fusarium graminearum and Trichoderma harzianum at the concentration of 60 ${\mu}g/ml$.

• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.156-160
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• 1997

The monoamine oxidase (MAO, EC 1.4.3.4) plays a central role in the metabolism of many amines including the neurotransmitter monoamines. MAO is a flavoprotein found exclusively in the mitochondrial outer membrane, occuring in the MAO-A and MAO-B subtypes. MAO-A deaminates serotonin and noradrenaline much better than phenethylamine (PEA) or benzylamine (BA), and is preferentially inhibited by clorgyline, whereas MAO-B prefers PEA and BA as substrates and is preferentially inhibited by deprenyl. MAO inhibitors were among the first drugs used in the treatment of depression, and it is known to be the inhibition of MAO-A which is important for the antidepressant effect of MAO inhibitors. For the purpose of evaluating MAO inhibitory activities from natural resources, three kinds of edible mushrooms were screened by tracing the inhibitory activities against rat brain mitochondrial MAO-A, utilizing serotonin as a substrate and rat liver mitochondrial MAO-B utilizing benzylamine as a substrate. Among the tested mushrooms, Ganoderma lucidium and Lentinus edodes showed the weak inhibitory activities against MAO-B.

• Analytical Science and Technology
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• v.5 no.4
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• pp.477-484
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• 1992

The mitochondrion was purified at 44% sucrose layer from pleurotus florida by using ultracentrifuge and sucrose density gradient method. Optimum pH and temperature of ATPase and ATP synthase were pH 7.4, $60^{\circ}C$ and pH 7.5, $57^{\circ}C$ respectively, also their Km values were determined as 11.6mM and 8.4mM. ATPase was activated at 5~6mM ATP substrate concentration, then ATP synthase was 5~10mM range ADP. ATPase/ATP synthase were $Mg^{2+}$-dependent enzyme, partially inhibited by their substrate, and then showed an none competitive inhibition pattern by $G_{418}$. Amino acid composition of ATPase/ATP synthase was as follows, hydrophobic amino acid residue was 50.5%, small residue, 56.1%, hydrogen bonding residue, 43.7% and helix breaking residue, 55.2%. Phosphatidyl choline, phosphatidyl ethanolamine and phosphatidyl glycerol were contained but not phosphatidyl inositol and phosphatidyl serine. Palmitate(51.31%), stearate(18.32%) and unsaturated fatty acids($C_{18:1}$, $C_{18:2}$ and $C_{16:1}$) were predominated.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.3
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• pp.155-160
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• 1979

Mechanical agitation in fermentation process enhances the fermentation activity of microbes by means of oxygen supply and frequent collision with substrate. However, the fermentation activity of microaerophilic bacteria is inhibited by the excess oxygen resulted from the mechanical agitation. On this account, a a strain of Lactobacillus bulgarius was cultured to know the inhibition effect of the mechanical agitation and determine the optimum conditions for tile process of lactic acid fermentation. The growth rate of L. bulgaricus and the consumption rate of tile substrate revealed an identical pattern in changes. The two rates were constant in the range of the modified Reynolds number of $1\times10^5\;to\;5\times10^5$ while they showed linear increase in the range of the modified Reynolds number of $1\times10^5\;to\;10\times10^5$. Under the conditions of the modified Reynolds number more than $10\times10^5$, the both rates decreased. At the modified Reynolds number of $10\times10^5$, the maximum specific growth rate and the saturation constant of L. bulgaricus were 0.58/hr and 6.74g/l, respectively.

• Applied Biological Chemistry
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• v.13 no.3
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• pp.237-242
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• 1970

Fifty strains of mold which isolated from the various sources were screened for the production of Naringinase which hydrolyse naringin, the 7-rhamnoe-glucoside of 4'.5.7. - trihydroxyflavanonin, the main bitter principle of citrus fruits and grape fruits. Of the 4 strains yielded naringinase with significant activity, S-1 strain was selected on the criterion of industrial application, and some properties of crude naringinase of this S-1 was investigated. The results obtained were as follows. 1. Naringenase obtained from S-1 strain has optimum pH range from 3.0 to 5.0 for its activity. 2. Production of naringinase was increased on the addition of naringin to the medium. 3. Hydrolysis of naringin with approporiate concentration of naringinase was carried out linerly up to 80% on the 0.1% substrate solution. 4. The optimum temperature for its activity was $50^{\circ}C$, and this enzyme was inactivated 80% of its total activity at $70^{\circ}C$ for 10 minutes, 40% at $60^{\circ}C$ for 30 minutes. But signifiant decrease of activity were not occurred by heat treatment at $50^{\circ}C$ for 2 hours. 5. Crude enzyme of the naringinase obtained from S-1 strain was competitively inhibited by addition of glucose on the substrate, and inhibitor constant of the glucose on the this enzyme was 1.5 Mol, and inhibition rate were linearly increased according to the increase of sucrose concentration and 56% of its total activity was inhibited at 1 Mol sucrose solution.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.7
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• pp.700-704
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• 2008

Nitrite and free ammonia have been known as substrate inhibitors in anaerobic ammonium oxidation. To reduce inhibitory effect of these substrates, the NH$_3$-N/NO$_2$-N ratio in the influent could be properly controlled in anaerobic ammonium oxidation process. Five kinds of NH$_3$-N/NO$_2$-N ratio were assayed in batch to find optimum NH$_3$-N/NO$_2$-N ratio, curtailing substrate inhibition. As the results of batch test, the highest T-N removal efficiency of 88% was obtained at 1.00 : 1.30 of NH$_3$-N/NO$_2$-N ratio. In addition, rate constants for ammonium and nitrite in zero-order kinetics were found to be the highest values as 7.66 mg/L$\cdot$hr and 11.89 mg/L$\cdot$hr at 1.00 : 1.30 ratio, respectively. However, as for the specific anammox activity, the ratio of NH$_3$-N/NO$_2$-N ratio was recommended as 1 : 1.15 which can maintain the highest SAA during continuous operation and preclude the accumulation of nitrite in the reactor.

• Journal of Korean Society of Forest Science
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• v.39 no.1
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• pp.57-63
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• 1978

Enzymatic hydrolysis of the substrate from Alnus hirsuta (Spach) Rupr (8-14years) was investigated using cellulase preparations of Trichoderma viride Pers. ex. Fr. SANK 16374 and conduced on the optimum reaction conditions of the cellulase on saccharification. The crude cellulase was produced by the submerged culture process and produced in the culture fluid was salted out quantitatively by the use of ammonium sulfate. The method of delignification from wood(Saw dust) was treated by the peracetic acid (PA) method. Reducing sugar was determined by the dinitrosalicylic acid (DNS) method. The results were summerized as follows; 1. The optimum pH of cellulase was 5.0 and the range of stability with respect to pH was generally from 4.0 to 6.0 2. The optimum temperature of cellulase was generally $40^{\circ}C$, but reducing sugar formation did not show significent differences at 5% levels in the reaction temperature from $40^{\circ}C$ to $50^{\circ}C$. 3. The redusing sugar were increased with increase of cellulase concentration. 4. The reducing sugar were decreased with increase of substrate concentration. 5. Fructose was a very good inhibitor of the enzyme from Trichoderma viride, but glucose inhibition was generally weak.

• Advances in Traditional Medicine
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• v.1 no.1
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• pp.8-27
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• 2000

Components of extracellular matrix and the matrix-degrading enzymes are some of the key regulators of tumor metastasis and angiogenesis. Hyaluronic acid (HA), a matrix glycosaminoglycan, is known to promote tumor adhesion and migration, and its small fragments are angiogenic. Until now, we have compared levels of hyaluronidase, an enzyme that degrade HA, in normal adult prostate, benign prostate hyperplasia and prostate cancer tissues and in conditioned media from epithelial explant cultures, using a substrate (HA)-gel assay and ELISA-like assay (Kim et al., unpublished results). The present review described an overall characterization of hyaluronidases and its application to human diseases. The hyaluronidases are a family of enzymes that have, until recently, deed thorough explication. The substrate for these enzymes, hyaluronan, is becoming increasingly important, recognized now as a major participant in basic processes such as cell motility, wound healing, embryogenesis, and implicated in cancer progression. And in those lower life forms that torment human beings, hyaluronidase is associated with mechanisms of entry and spread, e.g. as a virulence factor for bacteria, for tissue dissection in gas gangrene, as a means of treponema spread in syphilis, and for penetration of skin and gut by nematode parasites. Hyaluronidase also comprises a component of the venom of a wide variety of organisms, including bees, wasps, hornets, spiders, scorpions, sh, snakes and lizards. Of particular interest is the homology between some of these venom hyaluronidases and the enzyme found in the plasma membrane of mammalian spermatozoa, attesting to the ancient nature of the conserved sequence, a 36% identity in a 300 amino acid stretch of the enzyme protein. Clearly, hyaluronidase is of biological interest, being involved in the pathophysiology of so many important' human disorders. Greater effort should be made in studying this family of enzymes that have, until recently, been overlooked. Also, oriental medical application of the hyaluronidase will be discussed with respect to inhibition and suppression of inflammation and malignacy.

• Korean journal of applied entomology
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• v.34 no.3
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• pp.181-190
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• 1995

Malate dehydrogenase in the mosquito ovary after a blood meal, Aedes aegypti, was purified and characterized. MDH purification steps involved DEAE-Sepharose, S-Sepharose and Cibacron blue affinity chromatography. The purified MDH was 70,000 daltons in molecular weight and was a homodimer consisting of tow identical subunits. Optimal activity of purified MDH was obtained pH 9.0-9.2 in malate-oxaloacetate reaction and pH 9.8-10.2, in oxaloactate-malate reaction. With obtained pH 9.0-92 in malate-oxaloacetate reaction and pH 9.8-10.2, in oxaloactate-malate reaction. With malate as substrate, purified mitochondrial MDH (1.28$\times$${10}^{-4}$ M) had lower Km value than cytoplasmic MDH (8.92x${10}^{-3}$ M). MDH activity was inhibited by citrate, $\alpha$-ketoglutarate, and ATP. Inhibition of MDH activity by ATP and citrate was less in malate-oxaloacetate reaction and in oxaloacetate-malate reaction. MDH activity was completely inhibited by ATP in oxaloacetate-malate reaction and not inhibited by citrate in malate-oxaloacetate reaction. Temporal activity change of MDH is similar to that of isocitrate dehydrogenase in the ovary after blood feeding; their activities in the ovary began to rise at 18 hours after a blood meal, and reached at the maximal level at 48 hours.

• The Plant Pathology Journal
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• v.31 no.2
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• pp.140-151
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• 2015

Bacillus subtilis B006 strain effectively suppresses the cucumber fusarium wilt caused by Fusarium oxysporum f. sp. cucumerinum (Foc). The population dynamics of Foc, strain B006 and its surfactin over-producing mutant B841 and surfactin-deficient mutant B1020, in the rhizosphere were determined under greenhouse conditions to elucidate the importance of the lipopeptides excreted by these strains in suppressing Foc. Results showed that B. subtilis strain B006 effectively suppressed the disease in natural soil by 42.9%, five weeks after transplanting, whereas B841 and B1020 suppressed the disease by only 22.6% and 7.1%, respectively. Quantitative PCR assays showed that effective colonization of strain B006 in the rhizosphere suppressed Foc propagation by more than 10 times both in nursery substrate and in field-infected soil. Reduction of Foc population at the cucumber stems in a range of $0.96log_{10}ng/g$ to $2.39log_{10}ng/g$ was attained at the third and the fifth weeks of B006 treatment in nursery substrate. In field-infected soil, all three treatments with B. subtilis suppressed Foc infection, indicated by the reduction of Foc population at a range of $2.91log_{10}ng/g$ to $3.36log_{10}ng/g$ at the stem base, one week after transplanting. This study reveals that the suppression of fusarium wilt disease is affected by the effective colonization of the surfactin-producing B. subtilis strain in the rhizosphere. These results improved our understanding of the biocontrol mechanism of the B. subtilis strain B006 in the natural soil and facilitate its application as biocontrol agent in the field.