Porduction and Enzymatic Characteristics of ${\alpha}-Galactosidase$ from Aspergillus niger

Aspergillus niger에 의한 ${\alpha}-Galactosidase$의 생산 및 효소적 특성

  • Chun, Hyang-Sook (Department of Food & Nutrition, Ewha Woman's University) ;
  • Lee, Su-Rae (Department of Food & Nutrition, Ewha Woman's University)
  • 전향숙 (이화여자대학교 식품영양학과) ;
  • 이서래 (이화여자대학교 식품영양학과)
  • Published : 1988.02.01

Abstract

${\alpha}$-Galactosidase from Aspergillus niger as a possible enzyme for removal of flatulence factors in soybean foods was produced the highest in 120 hours in either Czapeck-Dox liquid medium or wheat bran solid medium. The most efficient carbon and nitrogen sources in Czapeck-Dox medium were raffinose and sodium nitrate, respectively, whereas the addition of the sources showed negative effects in wheat bran. pH optima for enzyme activity and stability were 4.0-5.0 and 3.5-6.5, respectively, and optimum temperature for stability was $40-50^{\circ}C$. Upon reaction on p-nitrophenyl-${\alpha}$-D-galactoside, Michaelis constant was 0.42 mM and maximum velocity was 152 ${\mu}moles$ substrate/minute/kg solid medium. Mercuric chloride acted as a strong noncompetitive inhibitor and p-chloromercuribenzoate, even in low concentration, acted as a competitive inhibitor. Crude ${\alpha}$-galactosidase hydrolyzed raffinose and stachyose completely, giving spots of monosaccharides only on thin-layer chromatogram.

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