Reinforced cooperative interaction between Bas1p and Bas2p improves cAMP production by Saccharomyces cerevisiae

Abstract:

[Objective] The effect of cooperative interaction between Bas1p and Bas2p on cAMP production by recombinant Saccharomyces cerevisiae strain was studied, and fermentation medium was preliminarily optimized. [Methods] Bas1p and Bas2p were over-expressed by using the co-integrated expressing strategy in the cAMP-producing strain G5. The growth and extracellular cAMP production of the resultant strain were investigated by fermentation in shaking flasks. The effects of the amount of yeast powder and peptone, and the precursor adenine added in media were studied. [Results] The cAMP concentration at 120 h produced by the G5 strain over-expressing Bas1p and Bas2p was 2 253.8 μmol/L when fermentation medium 1×YP was used, which was increased by 51.4% compared with control strain. The product concentration was further increased to 4 450.4 μmol/L when the content of yeast powder and peptone in media was doubled. By adding 0.5 g/L adenine in media, the cAMP concentration at 120 h was further increased to 5 314.3 μmol/L. [Conclusion] All those results proved that the reinforced cooperative interaction between Bas1p and Bas2p as well as medium optimization can improve cAMP production.

Key words:Saccharomyces cerevisae, Integrating vector, Cyclic adenosine monophosphate, BAS1-BAS2, Adenine