Continuous production of α-peptide using immobilized recombinant yeast cells: A model for continuous production of foreign peptide by recombinant yeast

Abstract

α-Peptide, a portion of Escherichia coli β-galactosidase, was cloned downstream of the yeast α-factor promoter and the signal peptide by one of the authors. In this study, we utilized recombinant yeast cells, transformed the α-peptide secretion vector and attempted continuous production of α-peptide as a model of foreign peptide production. The continuous production of α-peptide was performed by using immobilized recombinant yeast cells on a column reactor, after characterizing the secretion, using minimal and complex medium. Utilizing minimal medium, with a productivity of 100 000 U h −1 l −1, α-peptide was continuously produced for more than 200 h. We then attempted to improve the productivity of α-peptide by alternating minimal and complex medium. Utilizing this medium changing method, 1.4 times higher α-peptide was produced during 150 h of operation compared with that achieved only by feeding minimal medium.