利用已有一定胞外cAMP生产能力的酿酒酵母基因工程菌株G2，考察影响其生长和发酵生产胞外cAMP的关键工艺参数，进行初步的发酵工艺优化，为下一步的菌种改造和发酵过程优化奠定基础。结果表明，葡萄糖和酵母粉、蛋白胨含量及其配比是本研究考察参数中影响最大的因素，100 g/L葡萄糖和20 g/L酵母粉、40 g/L蛋白胨(简称为2*YP)培养基发酵的最大cAMP浓度可以达到(4 311.2±308.3) μmol/L，为100 g/L葡萄糖和10 g/L酵母粉、20 g/L蛋白胨(简称为1*YP)含量下最大值(1 972.0±122.5) μmol/L的2.186倍；添加前体物腺嘌呤(终质量浓度0.625 g/L)到前述2种培养基中可以进一步提高产量，分别达到(4 678.1±238.6)、(3 387.3±277.8) μmol/L，增幅分别为8.5%和71.8%；添加前体物次黄嘌呤到100 g/L葡萄糖和1*YP培养基中提高产量6.65%。

3’,5’-cyclic adenosine monophosphate (cAMP) is a key second messenger.It′s synthesis is strictly controlled.In this study, a genetically-modified yeast strain G2 in our lab was used for preliminary fermentation process optimization to improve extracellular cAMP production and investigate the key parameters.It showed that the most important parameters were the contents of glucose, yeast powder and peptone, and their ratio.The fermentation medium containing 100 g/L glucose and 2*YP (20 g/L yeast powder, 40 g/L peptone) led to the maximum cAMP concentration of (4 311.2±308.3) μmol/L, while the medium containing 100 g/L glucose and 1*YP produced cAMP (1 972.0±122.5) μmol/L.Adding precursor adenine to the forementioned media would further increase the cAMP concentration to (4 678.1±238.6) and (3 387.3±277.8) μmol/L, respectively.On the other hand, addition of precursor hypoxanthine led to the cAMP titer increase by 6.65% in the medium containing 100 g/L glucose and 1*YP.All of those results provided the clue for further optimization of fermentation process and modification of the cAMP-producing strains.