Invertase Production by Fed-batch Fermentations of Recombinant Saccharomyces cerevisiae

  • Koo, Ja-Hyup (Department of Food Science and Technology, Research Center for New-Biomaterials in Agriculture, Seoul National University) ;
  • Kim, Sang-Yong (Basic Research Team, R & D Center, TongYang Confectionery Co.) ;
  • Park, Yong-Cheol (Basic Research Team, R & D Center, TongYang Confectionery Co.) ;
  • Han, Nam-Soo (Department of Food Science and Technology, Research Center for New-Biomaterials in Agriculture, Seoul National University) ;
  • Seo, Jin-Ho (Department of Food Science and Technology, Research Center for New-Biomaterials in Agriculture, Seoul National University)
  • Published : 1998.06.01

Abstract

Fed-batch fermentations with different feeding media were carried out in order to increase the productivity of invertase expression using a recombinant Saccharomyces cerevisiae containing plasmid pRB58. Two batch cultures showed the expression of the SUC2 gene at a low concentration of glucose, suggesting that glucose concentration could be used as a control variable in a fed-batch operation mode. In the fed-batch culture by feeding the basal medium, cell mass and specific invertase activity did not increase much as compared with the simple batch culture. A series of fed-batch cultures revealed that the sucrose-supplemented medium increased cell mass whereas the enriched medium did specific invertase activity. To capitalize on the synergism of the sucrose-supplemented medium and the enriched medium, the sucrose-supplemented enriched medium was used as a feeding medium. The fed-batch culture using this medium resulted in a 2.4-fold increase in cell mass and a 1.9-fold enhancement in specific invertase activity compared with those of the batch culture. The increase in cell mass and specific invertase activity led to a marked increase in total invertase activity, 250U/ml, which was 6.3 times higher than that of the batch culture.

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