• Journal of Microbiology and Biotechnology
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• v.2 no.3
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• pp.204-208
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• 1992

Six kinds of oligosaccharides were obtained from the hydrolysate of copra galactomannan by a purified extracellular $beta$-mannanase from Penicillium purpurogenum. These oligosaccharides were identified as M-M, M-M-M, M-M, M-M-M-M, M-M-M-M-M and M-M-M-M-M-M; where G- and M- represent $\alpha$-l,6-D-galactosidic and $beta$-l,4-mannosidic linkages, respectively. The mode of action of mannanase on galactomannan is discussed on the basis of the structure of these oligosaccharides.

• Journal of Applied Biological Chemistry
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• v.51 no.6
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• pp.292-295
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• 2008

Three kinds of oligosaccharides were obtained from the hydrolysate of brown copra meal galactomannan by a purified extracellular ${\beta}$-mannanase from Trichoderma sp. These oligosaccharides were identified as Man-Man, ${Gal^2}{Man_3}(6^2 mono-O-{\alpha}-D-galactopyranosyl-4-O-{\beta}-D-mannotriose)$, and ${Gal^2}{Man_6}(6^2-mono-O-{\alpha}-D-galactopyranosyl-4-O-{\beta}-D-mannohexaose)$, where Gal- and Man-represent ${\alpha}$-1,6-D-galactosidic and ${\beta}$-1,4-mannosidic linkages, respectively. The mode of action of ${\beta}$-mannanase on brown copra meal galactomannan is described on the basis of the structure of these oligosaccharides.

• Journal of Microbiology and Biotechnology
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• v.3 no.3
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• pp.194-198
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• 1993

${\beta}-1$, 4-Mannobiose was prepared by the enzymatic hydrolysis of brown copra meal and the subsequent elimination of mono-saccharides from the resultant hydrolysate with a yeast. The enzyme system hydrolyzed brown copra meal and produced monosaccharides and $\beta$-1, 4-mannobiose without other oligomers at the final stage of the reaction. Brown copra meal (30 g) was hydrolyzed at $50^{\circ}^C$ and pH 5 for 48 hr with the crude enzyme solution (300 ml) from Penicillium purpurogenum. By the elimination of monosaccharides from the hydrolysis products with a yeast (Candida parapsilosis var. komabaensis k-75), 5.2 g of crystalline mannobiose was obtained without the use of chromatographic techniques. After 50 hours of yeast cultivation, the total sugar content fell from 3.5% to 2.4%, and the average degree of polymerization rose from 1.8 to 2.2.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.3
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• pp.509-514
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• 1994

Penicillium purpurogenum , which produces a copra galactomannan degrading enzyme extracellularyl, was isolated from soil , and its properties and formation condition of mannooligosaccharides were investigated. The optimum ph and temperature for the activity of the mannanase were 5.5 and 55$^{\circ}C$, respectively. The mannanase was stable in between pH 3.5 and 7.0 after 2 hr incubation at 3$0^{\circ}C$ lost 90% of the original activity after incubation at 55$\AA$ and pH 5.5 for 2 hr. With two different substrate concentration, hydrolysis of white coprameal proceeded rapidly at the early stage of the reaction, but gradually solwed thereafter especially at a higher concentration of copra meal (20 %). The enzyme hydrolyzed white copra meal to monosaccharides, mannobiose and mannotriose at the final stage of the reaction.

• Journal of Microbiology and Biotechnology
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• v.1 no.2
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• pp.90-95
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• 1991

A ${\alpha}-galactosidase{\;}({\alpha}-D-galactoside$ galactohydrolase; EC 3.2.1.22) was purified from the culture filtrate of Penicillium purpurogenum by DEAE-cellulose column chromatography, gel filtration of Bio gel p-l00, and subsequent SP-Sephadex C-25 chromatography. The final preparation thus obtained showed a single band on polyacrylamide disc-gel and SDS-polyacrylamide gel electrophoresis. The molecular weight and isoelectric point were determined to be 63,000 and pH 4.0 by SDS-polyacrylamide gel electrophoresis and isoelectric focusing, respectively. The galactosidase exhibited maximum activity at pH 4.5 and $55^{\circ}C$, and was stable between pH 2 and 5, and also stable up to $40^{\circ}C$. The enzyme activity was not affected considerably by treatment with other metal compounds except mercuric chloride and silver nitrate. Copra galactomannan was finally hydrolyzed to galactose, mannose and mannobiose through the sequential actions of the purified galactosidase and mannanase from the same strain. The enzyme hydrolyzed melibiose and raffinose, but not lactose.

• Microbiology and Biotechnology Letters
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• v.26 no.4
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• pp.316-322
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• 1998

An ${\alpha}$-D-galactosidase (${\alpha}$-D-galactoside galactohydrolase, EC 3. 2. 1. 22) from sunflower seed was purified by affinity chromatography using N-$\varepsilon$-aminocaproyl-${\alpha}$-D-galactopyranosylamine coupled to sepharose and its properties were examined. The specific activity of the purified enzyme, tested with p-nitrophenyl-${\alpha}$-D-galactopyranoside as substrate, was 291.66 units/mg protein, representing an 115-folds purification of the original crude extract. The final preparation obtained from by Sephadex G-25 chromatography showed a single band on SDS-polyacrylamide gel electrophoresis. The molecular weight was determined to be 42,000 by SDS-polyacrylamide gel electrophoresis. The purified galactosidase showed maximum activity at pH 4.5 and 55$^{\circ}C$, and was stable in the pH and temperature ranges of 4.0 to 5.0 and 30 to 55$^{\circ}C$, respectively. The enzyme activity was inhibited by Ag$\^$2+/, Hg$\^$2+/ and Co$\^$2+/. The enzyme activity was not affected considerably by treatment with other metal compounds. The enzyme liberated galactose from melibiose, raffinose, copra galactomannan, guar gum and locust bean gum by TLC, and also the hydrolysis rate of substrate was compared by HPLC.