利用转录调控因子Bas1p和Bas2p协同作用提高酿酒酵母cAMP产量的研究

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

摘要:

【目的】研究转录调控因子Bas1p和Bas2p协同作用对重组酿酒酵母(Saccharomyces cerevisiae)胞外cAMP产生的影响，初步优化发酵培养基。【方法】通过共整合表达策略，在cAMP产生菌酿酒酵母G5中超表达Bas1p和Bas2p，摇瓶发酵实验考察了Bas1p和Bas2p协同作用对菌株生长及胞外cAMP产生的影响，进一步考察了酵母粉和蛋白胨含量及前体物腺嘌呤对菌株生长和cAMP产生的影响。【结果】超表达Bas1p和Bas2p使菌株在1×YP培养基中发酵120 h时的cAMP产量较出发菌株提高51.4%，达到2 253.8 μmol/L；将1×YP中的酵母粉和蛋白胨含量翻倍(即2×YP培养基)发酵120 h时的cAMP产量提高至4 450.4 μmol/L；在2×YP培养基中添加0.5 g/L浓度的腺嘌呤时，cAMP产量进一步提高至5 314.3 μmol/L。【结论】强化Bas1p和Bas2p的协同作用及相应地优化培养基组分有助于酿酒酵母胞外cAMP生产。

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.