Isolation and Characterization of Enterobacter sp. Producing Galacto-oligosaccharides

  • YANG, JI-WON (Department of Chemical Engineering, BioProcess Engineering Research Center, KAIST) ;
  • HYUN-JAE SHIN (Department of Chemical Engineering, BioProcess Engineering Research Center, KAIST) ;
  • SANG-PIL YEOM (Department of Chemical Engineering, BioProcess Engineering Research Center, KAIST) ;
  • BYUNG-DAE YUN (Genetic Engineering Research Institute, KIST) ;
  • MIN-HONG KIM (R & D Center, Miwon Co., Ltd)
  • 발행 : 1994.12.01

초록

Enterobacter sp. producing -$\beta$-galactosidase with high transgalactosylation activity was isolated from dairy wastewater. The isolate had common biochemical features to E. aerogenes and E. cloacae. Enzyme production increased as the cell mass increased with optimum enzyme activity of 0.21 Unit/mg-protein (o-nitro-phenyl-$\beta$ -D-galactoside (ONPG) as substrate) until 8 hr of culture. Whole cells permeabilized by toluene were used to produce galacto-oligosaccharide. Optimum toluene concentration, temperature and pH for -$\beta$-galactosidase activity of permeabilized whole cells were 10% (v/v), $50^{\circ}C$ and 6.0, respectively. A maximum of 38% (w/w) of galacto-oligosaccharide was obtained with lactose concentration of 20% (w/w) at $40^\{\circ}C$ and pH 6.0.

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