Construction of a flocculent Saccharomyces cerevisiae strain secreting high levels of Aspergillus niger β-galactosidase

L. Domingues, J. Teixeira, M. Penttilä, N. Lima

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A flocculent Saccharomyces cerevisiae strain secreting Aspergillus niger β-galactosidase activity was constructed by transforming S. cerevisiae NCYC869-A3 strain with plasmid pVK1.1 harboring the A. niger β-galactosidase gene, lacA, under the control of the ADH1 promoter and terminator. Compared to other recombinant S. cerevisiae strains, this recombinant yeast has higher levels of extracellular β-galactosidase activity. In shake-flask cultures, the β-galactosidase activity detected in the supernatant was 20 times higher than that obtained with previously constructed strains (Domingues et al. 2000a). In bioreactor culture, with cheese-whey permeate as substrate, a yield of 878.0 nkat/gsubstrate was obtained. The recombinant strain is an attractive alternative to other fungal β-galactosidase production systems as the enzyme is produced in a rather pure form. Moreover, the use of flocculating yeast cells allows for enzyme production with high productivity in continuous fermentation systems with facilitated downstream processing.

Original languageEnglish
Pages (from-to)645-650
JournalApplied Microbiology and Biotechnology
Issue number5
Publication statusPublished - 22 Apr 2002
MoE publication typeA1 Journal article-refereed



  • Fermentation
  • Saccharomyces cerevisiae
  • Aspergillus niger
  • Recombinant strain
  • continuous fermentation

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