ISSN:
1432-0614
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Summary A Saccharomyces cerevisiae strain harbouring the recombinant plasmid pSMF38TMA was cultured in a jar fermentor under the control of glucose concentration. In the recombinant plasmid, the mouse α-amylase gene was fused to the S. cerevisiae SUC2 promoter. When glucose concentration in the medium was controlled at 10 g/l, the gene expression was completely repressed. On the other hand, the α-amylase was produced and secreted in the medium at a very high level, around 200 mg/l as evaluated from the specific activity of commercially available human salivary amylase, when the glucose was kept at 0.15 g/l. This amount was almost 20-fold that obtained at 10 g/l glucose. The specific growth rate of the yeast in this culture was almost 60% of that attained with 10 g/l glucose. To obtain higher cell growth and productivity, the yeast was at first cultured at 2 g/l glucose and the concentration was then lowered to 0.15 g/l. By this control of the glucose concentration, on-off regulation of gene expression from the SUC promoter could be attained.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00184981
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