• Korean Journal of Agricultural Science
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• v.18 no.1
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• pp.49-73
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• 1991

To elucidate enzymatic properties of $\alpha$-galactosidases (EC3, 2, 1, 22) from germinated soybean and Aspergillus niger changes in the enzyme activities and oligosaccharide contents during germination of soybean were determined and $\alpha$-galactosidases from germinated soybean and wheat bran culture of Aspergillus niger were purified by ammonium sulfate fractionation, ion exchange chromatography and gel filtration. Their chemical and enzymatic properties were investigated and the results obtained were summarized as follows : 1. $\alpha$-Galactosidase activity of soybean was maximized when it was germinated at $25^{\circ}C$ for 120 hours. And raffinose and stachyose in soybean were decomposed completely after 96 hours and 120 hours of germination, respectively. 2. The highest level of $\alpha$-Galactosidase activity was obtained when Aspergillus niger was grown on wheat bran medium at $30^{\circ}C$ for 96 hours. 3. Soybean $\alpha$-galactosidase was purified by 6.6 fold by ammonium slufate fractionation, ion exchange chromatography on DEAE-Cellulose and Sephadex A-50., and gel filtration on Sephadex G-150. Its specific activity was 825 units/mg protein and the yield was 2.5% of the total activity of crude extracts. 4. Aspergillus niger $\alpha$-galactosidase was purified by 23.7 fold. Its specific activity was 1,229 units/mg protein and the yield was 14% of the total activity of wheat bran culture. 5. The purified $\alpha$-galactosidases of soybean and Aspergillus niger were found to be homogeneous by polyacrylamide gel electrophoresis and by HPLC. 6. Chemical properties of the purified $\alpha$-galactosidases were : 1) The soybean $\alpha$-galactosidase was monomeric and its molecular weight was estimated to be 30,000 by SDS-PAGE whereas the Aspergillus niger $\alpha$-galactosidase was a tetrameric glycoprotein which consisted of identical subunits with molecular weight of 28,000 each.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.332-338
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• 2002

A strain YB-4 producing the extracellular $\alpha$-galactosidase was isolated from soil, and has been identified as Streptomyces sp. on the basis of its cultural, morphological and physiological properties. The partially purified $\alpha$-galactosidase was most active on paranitrophenyl-$\alpha$-D-galactopyranoside at pH 6.0 and 6$0^{\circ}C$. The enzyme retained 90% of its maximum activity between pH 4.0 and pH 10.0 after pre-incubation for 1 h. The enzyme was able to hydrolyze oligomeric substrates such as melibiose, raffinose and stachyose to liberate galactose residue, indicating that the $\alpha$-galactosidase of Steptomyces sp. YB-4 hydrolyzed $\alpha$-1,6 linkage.

• Microbiology and Biotechnology Letters
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• v.32 no.2
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• pp.128-134
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• 2004

A bacterium producing the $\alpha$-galactosidase was isolated from Korean soybean paste. The isolate YB-42 has been identified as Bacillus licheniformis on the basis on its 16S rRNA sequence, morphology and biochemical properties. The $\alpha$-galactosidase activity was detected in both the culture supernatant and the cell extract of B. licheniformis YB-42. The partially purified extracellular $\alpha$-galactosidase was obtained from the culture supernatant by DEAE-Sepharose column and Q-Sepharose column chromatography. The enzyme showed the maximum activity for hydrolysis of para-nitrophenyl-$\alpha$-D-galactopyranoside (pNP-$\alpha$Gal) at pH 6.5 and $45^{\circ}C$. It was able to hydrolyze oligomeric substrates such as melibiose, raffmose and stachyose to liberate galactose residue, indicating that the a-galactosidase of B. licheniformis YB-42 hydrolyzed $\alpha$-1,6 linkage. The hydrolyzing activity of $\alpha$-galactosidase for both pNP-$\alpha$Gal and melibiose was dramatically decreased by galactose. Both glucose and mannose inhibited the activity for pNP-$\alpha$Gal less than galactose.

• Microbiology and Biotechnology Letters
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• v.19 no.5
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• pp.477-486
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• 1991

To elucidate enzymatic properties of a-glactosidase (EC 3.2.1.22) from Asp. niger, a-galactosidase from wheat bran culture was purified by ammonium sulfate fractionation, ion exchange chromatography and gel filtration. And then its enzymatic propeties were investigated. The highest level of $\alpha$-galactosidase activity was obtained when Asp. niger was grown on wheat bran medium at $30^{\circ}C$ for 96 hours. The $\alpha$-galactosidase was purified by 23.7 fold by ammonium sulfate fractionation, ion exchange chromatography on DEAE-Celluose and Sephadex A-50, and gel filtration on Sephadex G-150 and its specific activity was 1,229 Unitslmg protein and the yield was 14% of the total activity of wheat bran culture. The purified $\alpha$-galactosidase was found to be homogeneous by polyacrylamide gel electrophoresis and HPLC. The $\alpha$-galactosidase was a tetrameric glycoprotein which consisted of identical subunits with molelcular weight of 28,000 each by SDS-PAGE and isoelectric point was determined analytical isoelectric focusing to be pH 4.6. The optimal temperature and pH for the $\alpha$-galactosidase activity were $40^{\circ}C$ and pH 6.5, respectively, and 54% of its activity was lost by heating at $60^{\circ}C$ for 10 mins, It was appeared to have higher affinty to raffinose than to stachyose. The K, value and activation energy of $\alpha$-galactosidase were 5.0 mM and 8.515 Kcal per mole for p-nitrophenyl- $\alpha$--D-galactopyranoside, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.5
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• pp.516-521
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• 2014

A bacterium producing ${\alpha}$-galactosidase (${\alpha}$-$\small{D}$-galactoside galactohydrolase, EC 3.2.1.22) was isolated. The isolate, KM-1 was identified as Bacillus coagulans based on its 16S rRNA sequence, morphology, and biochemical properties. ${\alpha}$-Galactosidase activity was detected the culture supernatant of B. coagulans KM-1. The bacterium showed the maximum activity for hydrolyzing para-nitrophenyl-${\alpha}$-$\small{D}$-galactopyranoside (pNP-${\alpha}Gal$) at pH 6.0 and $50^{\circ}C$. It hydrolyzed oligomeric substrates such as melibiose, raffinose, and stachyose liberating a galactose residue, indicating that the B. coagulans KM-1 ${\alpha}$-galactosidase hydrolyzed ${\alpha}$-1,6 linkage. The results suggest that the decreased stachyose and raffinose contents in fermented soybean meal are due to the ${\alpha}$-galactosidase activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.844-850
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• 1997

$\alpha$-Galactosidase was partially purified from the culture filtrate of pichia guilliermondii by Mannobiose-Sepharose affinity column chromatography. The galactosidase exhibited maximum activity at pH 4.5 and 4$0^{\circ}C$, and was stable in the pH and temperature ranges of 4 to 5.5 and 30 to 6$0^{\circ}C$, respectively. The enzyme was inhibited by $Hg^{2+}$ and $Ag^{2+}$. The enzyme activity was ot affected considerably by treatment with other metal compounds. The enzyme hydrolyzed melibiose to galactose and glucose, raffinose to galactose and sucrose, and $Gal^{3}Man_{3}(6^{3}-$\alpha$-galactosyl-1,4-mannotriose)$ to galactose and mannotriose. On the contrary, it could not hydrolyze $Gal^{3}Man_{4}(6^{3}-galactosyl-1,4-$\alpha$-mannotetraose)$.

• Applied Biological Chemistry
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• v.34 no.3
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• pp.249-257
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• 1991

To elucidate enzymatic properties of ${\alpha}-galactosidase$ (EC 3, 2, 1, 22) from germinated soybean, changes in the enzyme activities and oligosaccharide contents during germination of soybean were determined. ${\alpha}-Galactosidase$ from germinated soybean was purified by ammonium sulfate fractionation, ion exchange chromatography and gel filtration. Their chemical and enzymatic properties was investigated. ${\alpha}-galactosidase$ activity of sobeam was maximized when it was germinated at $25^{\circ}C$ for 120 hour. Raffinose and stachyose in soybean were decomposed completely after 96 hours and 120 hours of germination, respectively. Soybean ${\alpha}-galactosidase$ was purified by 6.6 fold by ammonium sulfate fractionation, ion exchange chromatography on DEAE-Cellulose and Sephadex A-50, and gel filtration on Sephadex G-150. Its specific activity was 825 Units/mg protein and the yield was 2.5% of the total activity of crude extracts. The purified ${\alpha}-galactosidase$ of soybean was found to be homogeneous by polyacrylamide gel electrophoresis and by HPLC. Isoelectric point of soybean ${\alpha}-galactosidase$ was determined analytical isoelectric focusing to be pH 4.8. The soybean ${\alpha}-galactosidase$ was monomeric and its molecular weight was estimated to be 30,000 by SDS-PAGE. The optimal temperature and pH for the soybeam ${\alpha}-galactosidase$ activity were $40^{\circ}C$ and pH 6.0 and 75% of its activity was lost by heating at $60^{\circ}C$ for 10 min. The enzyme was appeared to have higher affinity to raffinose than to stachyose. The Km value of soybean enzyme was 5.3 mM for ${\rho}-nitrophenyl-{\alpha}-D-galactopyranoside$ and the activation energy on PNPG was calculated to be 13.02 Kcal per mole.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.694-697
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• 1993

Soymilk was cultured by various human large intestinal bacteria and lactic acid bacteria; Bifidobacterium longum, Lactobacillus acidophilus, Baeteroides fragilis, Eubacterium limosum, Clostridium perfringens and Escherichia coli. Among them, only B. longum utilized raffinose and stachyose actively which are major oligosaccharides present in soymilk by producing active ${\alpha}-galactosidase$ and produced greatest acid. Number of colony forming unit of B. longum reached $1.5{\times}10^{8}$ after 16 hr culture in soymilk. Also Bifidobacterium longum produced the highest level of ${\alpha}-galactosidase,\;{\beta}-galactosidase\;and\;{\alpha}-galactosidase$, in soymilk during culture.

• Journal of Applied Biological Chemistry
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• v.43 no.3
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• pp.141-146
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• 2000

Glycosidase activities were tested from the grape berries, Vitis labruscana B. Takasumi. Among various glycosidases, $\alpha$-D-galactosidase was found to be the most active in the flesh and other glycosidases were considerably active in the order of the following: $\alpha$-D-mannosidase>$\alpha$-D-glucosidase>$\beta$-D-glucosidase>$\beta$-D-galactosidase. In the seeds, $\alpha$-D-glucosidase activity was the highest and other glycosidases such as $\alpha$-D-galactosidase, $\beta$-D-glucosidase, and $\beta$-D-galactosidase were still significantly active. The $\alpha$-D-galactosidase in the grape flesh was purified over 83-folds through salting-out with $(NH_4)_2SO_4$ and a series of chromatographies employing Sephadex G-50, Octyl-Sepharose, Q-Sepha- rose, and Biogel P-100. The enzyme was a monomer of 45 kDs as determined through SDS-PAGE and Sephacryl S-200 chromatography. The purified enzyme showed a preference of $\alpha$-D-galactose to $\beta$-D-galactose as a substrate about 5.4 times. Sulfhydryl specific reagents such as N-ethylmaleimide and iodoacetamide significantly inhibited the enzyme activity to the extents of 48 and 52% of its initial activity, respectively. The optimumpH range of $\alpha$-D-galactosidase was around 6.5-7.0. The enzyme activity increased by 46% in the presence of 1mM $Fe^{2+}$.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.180-185
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• 2006

${\alpha}$-Galactosidase was partially purified from the culture filtrate of Debaryomyces sp. by Mannobiose-Sepharose affinity column chromatography. The galactosidase exhibited maximum activity at pH 4.0 and $60^{\circ}C$, and was stable in the pH and temperature ranges of 3 to 4.5 and 30 to $50^{\circ}C$, respectively. The enzyme was inhibited by $Hg^{2+}\;and\;Ag^{2+}$. The enzyme activity was not affected considerably by treatment with other metal compounds. The enzyme hydrolyzed melibiose to galactose and glucose, raffinose to galactose and sucrose, and $Gal^3Man_3$ ($6^3-{\alpha}$-galactosyl-1,4-mannotriose) to galactose and mannotriose. On the contrary, it could not hydrolyze $Gal^3Man_4$ ($6^3-{\alpha}$-galactosyl-1,4-mannotetraose).