Production of antithrombotic hirudin in GAL1-disrupted Saccharomyces cerevisiae

Abstract

A gratuitous strain was developed by disrupting the GAL1 gene (galactokinase) of recombinant Saccharomyces cerevisiae harboring the antithrombotic hirudin gene in the chromosome under the control of the GAL10 promoter. A series of glucose-limited fed-batch cultures were carried out to examine the effects of glucose supply on hirudin expression in the gratuitous strain. Controlled feeding of glucose successfully supported both cell growth and hirudin expression in the gratuitous strain. The optimum fed-batch culture done by feeding glucose at a rate of 0.3 g h(-1) produced a maximum hirudin concentration of 62.1 mg l(-1), which corresponded to a 4.5-fold increase when compared with a simple batch culture done with the same strain.

Characterization of an <small>L</small>-Arabinose Isomerase from <i>Bacillus thermoglucosidasius</i> for <small>D</small>-Tagatose Production

“…7) However, the industrial production of D-tagatose should be done in a moderately acidic pH range at low temperature (up to 40 C) to prevent browning and by-product formation. 8) For these purposes, novel L-AIs that are active at slightly low pH (pH 5.0-7.0) and temperature have been isolated from Shewanella sp. ANA-3, Lactobacillus sakei, Escherichia coli, and Bacillus subtilis.…”

Systems for applied gene control in Saccharomyces cerevisiae

“…In the absence of galactokinase, and using low levels of glucose or a nonrepressive carbon source, galactose can act as an inducer without being consumed. This strategy has been successfully used to express antithrombotic hirudin in S. cerevisiae, up to 62.1 mg/l, when transcription of its cDNA was driven by a GAL10 promoter under glucose-limited conditions (Kim et al 2004). …”

Intensification of yeast production with microbubbles

“…Yeast is the key raw material in many consumer products, for instance, in the production of beverages (Heux et al, 2006), antibiotics (Kim, 2004) and recombinant proteins (Kato et al, 1998). In addition, it plays an essential role in the energy sector for the production of biomass or biofuel.…”