• Journal of the East Asian Society of Dietary Life
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• v.23 no.6
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• pp.789-798
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• 2013

In the present study, optimization on ${\beta}$-glucanase-assisted extraction was made in order to isolate waxy barley starch from domestic cultivar using the D-optimal design suitable for response surface methodology (RSM). The results demonstrated that the amount of enzyme was found to be a major influencing factor on the extraction yield, which was substantially increased by increasing the amount of enzyme. It was also influenced by the reaction time and amount of water addition; however, the two factors were less influential than the amount of enzyme. The optimized condition by RSM for the reaction time was found to be 2.63 hours and amount of enzyme 1.7%, and amount of water addition 4.38 times the weight of raw material. With the enzyme treatment, the starch content in residues (R), particularly in R1 and R5, was reduced considerably, resulting in an increase in the extraction yield and therefore primarily and effectively releasing B-type starch small granule confirmed by scanning electronic microscopy. In addition, the study determined the physicochemical properties of isolated waxy starch (i.e., purity, water adsorption capacity, thermal properties, rheology and starch morphology) and compared them with those from the enzyme-not treated sample. It was found that they were almost similar to each other, except for the purity of starch, which was lower in the enzyme-treated sample than in the enzyme-not treated one.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.2
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• pp.129-134
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• 1988

Enzymatical properties of Streptomyces sp. S-45 producing chitinase and ${\beta}$-1.3-glucanase isolated from soil were investigated. Chitinase activity was 3.01(U/ml) and ${\beta}$-1.3-glucanase activity was 2.49(U/ml). The optimum medium for mycolytic enzyme production of strain was composed of 0.7% colloidal chitin, 0.3% glucose, 0.5% asparagine, 0.2% peptone, 0.01% NaCl, 0.01% $K_2HPO_4$ and 0.01% $MgSO_4{\cdot}7H_2O$ in intial pH 7.0. The optimal condition for mycolytic enzyme activities were: pH 6.5-7.0, $45-50^{\circ}C$. Enzyme activities were activated by metal ion as $10^{-2}M\;Co^{{+}{+}}$, $Cu^{{+}{+}}$, $Mn^{{+}{+}}$, $Al^{{+}{+}{+}}$ and $10^{-3}M\;Sn^{{+}{+}}$ but $Ag^{{+}{+}}$, $Hg^{{+}{+}}$ inhibited.

• Journal of Microbiology and Biotechnology
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• v.24 no.12
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• pp.1699-1706
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• 2014

A lichenase gene (mt-lic) was identified for the first time through function-based screening of a soil metagenomic library. Its deduced amino acid sequence exhibited a high degree of homology with endo-${\beta}$-1,3-1,4-glucanase (having both lichenase and chitosanase activities), encoded by the bgc gene of Bacillus circulans WL-12. The recombinant lichenase overexpressed and purified from Escherichia coli was able to efficiently hydrolyze both barley ${\beta}$-glucan and lichenan. The enzyme showed maximal activity at a pH of 6.0 at $50^{\circ}C$, with Azo-barley-glucan as the substrate. The metal ions $Mn^{2+}$, $Mg^{2+}$, $Ca^{2+}$, and $Fe^{2+}$ enhanced the enzymatic activity, whereas the $Cu^{2+}$ and $Zn^{2+}$ ions inhibited the enzymatic activity. The $K_m$ and $V_{max}$ values of the purified lichenase were determined to be 0.45 mg/ml and 24.83 U/min/mg of protein, respectively.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.648-653
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• 2017

The aim of this study was to select various fungal strains indigenous to Korea that have the potential to produce cellulases, including filter paper activity (FPase), $endo-{\beta}$-1,4-glucanase (EG), and ${\beta}-glucosidase$ (BGL). Among the 25 species of Ascomycetes and the 32 species of Basidiomycetes tested in this study, the Bjerkandera adusta KUC10565, Heterobasidion orientale KUC10556, Hyphoderma praetermissum KUC10609, and Trichoderma harzianum KUC1716 all exhibited remarkably high FPase activity. In addition, the T. harzianum KUC1716 showed high levels of EG and BGL activity. This strain has been selected for further study because of their enzymatic potential.

• Microbiology and Biotechnology Letters
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• v.23 no.6
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• pp.659-664
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• 1995

To improve stability of recombinant DNA pLC1 encoding endoglucanase gene and pGL1 encoding $\beta $-glucosidase gene, DNA fragments of genes coding endoglucanase and $\beta $-glucosidase were cloned within the recA gene on a pDR1453, and the pDRE10 and pDRG20 of recombinant plasmids were integrated into the recA gene on the E. coli 1100 chromosomal DNAs. The stability of inheritance was completely maintained in E. coli 1100; Transformants E. coli 1100/pDREIO and pDRG20 were expressed well by recA promoter and increased endoglucanase and $\beta $-glucosidase activities. This method can be used as a model to improve the stability of recombinant plasmid in large scale culture.

• Mycobiology
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• v.29 no.3
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• pp.173-175
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• 2001

The fruit body of Ramaria botrytis DGUM 29001 was used to determine enzyme activities of fruit body. The specific activity of laccase was the highest(6.5 unit/mg$\cdot$protein) and that of $\alpha$-amylase and xylanase was relatively high. However, little or no enzyme activity of $\beta$-glucosidase, CMCase, exo-$\beta$-1,4-glucanase, chitinase, lipase and protease was found.

• The Plant Pathology Journal
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• v.26 no.1
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• pp.63-69
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• 2010

The effect of Acibenzolar-S-methyl (ASM) and Rahnella aquatilis Ra39 against apple fire blight disease caused by Erwinia amylovora were tested as a possible alternative to streptomycin. In vitro studies, no inhibition effect against the pathogen was found when ASM was tested. Under greenhouse conditions, application of R. aquatilis Ra39 with the highly susceptible M26 rootstock resulted in a marked disease suppression. Application of ASM and strain Ra39 caused a high decrease of the disease, 82% and 58% respectively; this was correlated with a reduction of the growth of the pathogen within host plants up to 64% and 49.5% respectively. Further studies in the field under artificial infection condition during full bloom revealed that application of ASM and R. aquatilis Ra39 with Gala variety resulted in a control effect up to 21 and 29% respectively. In physiological studies, enhanced activities of PR-proteins (chitinase and $\beta$-1, 3-glucanase) were detected, which are well known as biochemical markers for systemic acquired resistance. Application of ASM to apple shoots caused the highest chitinase activity followed by strain Ra39. The enzyme activity was increased after 2, 4 and 6 days from application. In addition, ASM-treatment caused the higher $\beta$-1, 3-glucanase activity than strain Ra39. Maximum enzyme activity was recorded after 6 days from application and then decreased after 8 and 10 days from application.

• Microbiology and Biotechnology Letters
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• v.28 no.4
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• pp.195-201
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• 2000

Glucoamylase of Saccharomyces diastaticus is produced as a large precursor composed of signal peptide (21 amino acid residues), Thr and Ser-rich region and functional glucoamylase. To evaluate the utility of the glucoamylase signal peptide (GSP) for the secretion of foreign proteins, four types of GSP mutants (ml : Pro-18 longrightarrowLeu-18, m2 : Tyr-13 longrightarrowLeu, m3 : Ser-9longrightarrowLeu-9, m4 : Asn-5 longrightarrowPro-5) were constructed and secretion efficiency of each mutant was compared with that of native GSP by the expression and secretion of Bacillus subtilis CMCase under the control of GAP in N-terminal domain and hydrophobic domain. n mutant 4, a polar amino acid was replaced by a helix - breaking Pro residue. CMCase activity assay and Western blot analysis revealed that CMCase secretion by GSP mutants replaced by Leu were increased compared with native GSP. In the case of m2 and m3, the substitution of Leu for Tyr-13 and Ser-9 in the hydrophobic region resulted in a twofold increase in the extracellular CMCase activity.

• Journal of Applied Biological Chemistry
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• v.62 no.3
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• pp.293-297
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• 2019

Leaf rust is the most widespread and destructive fungal disease, and outbreaks have always caused considerable losses in wheat yields. Thus, worldwide increases in wheat production depend on the development of leaf rust-resistant wheat varieties. In this study, we evaluated the resistance of forty Korean wheat cultivars to leaf rust at the seedling stage. Only two Korean wheats, Ol and Jonong, were resistant to leaf rust, whereas the remaining thirty-eight Korean wheats were susceptible to leaf rust. The Ol and Jonong varieties presented larger dry seed weights and higher antioxidant activity in response to leaf rust than the susceptible wheat varieties. No differences in ${\beta}$-1,3-glucanase activity or chlorophyll content between resistant and susceptible wheat varieties were observed. Overall, these results are important for the development of wheat varieties that are highly resistant to leaf rust and to understand the underlying mechanisms that confer leaf rust resistance.

• The Korean Journal of Mycology
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• v.16 no.4
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• pp.214-219
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• 1988

Factors affecting protoplast formation and reversion were investigated in Pleurotus sapidus kalchbr. For release of protoplast, enzyme mixture of Novozyme 234, ${\beta}-D-glucanase$ and ${\beta}-glucuronidase$ was most effective, when mycelium of 0.6 M sucrose solution as osmotic stabilizer without addition of buffer solution. The yield of protoplast was highest with mycelium cultured for 4 days on mushroom complete agar medium at ${30}^{\circ}C$. Protoplasts of Pleurotus sapidus were reverted to normal hyphal growth with maximum reversion frequency of 2% on Mushroom complete agar medium stabilized with 0.6 M sucrose solution and covered by 0.75% agar layer.