Abstract: Provided is a yeast strain capable of excessively synthesizing cAMP and its construction method and fermentation technique thereof, and application in the field of medicine, animal husbandry, food or chemical industry. The yeast strain includes first and second gene modifications, wherein the first gene includes protein kinase A (PKA) catalytic subunit encoding genes TPK1, TPK2 and TPK3, by modifying the first gene, the activity or expression of PKA is completely inhibited, so that feedback inhibition to cyclic adenosine monophosphate (cAMP) is eliminated, but at the same time, the growth of the yeast is inhibited; and the second gene modification eliminates growth inhibition caused by the first gene modification, so that the yeast grows normally, and the cAMP yield by the yeast is increased, wherein the increase of the cAMP yield is relative to the cAMP yield by an unmodified yeast. The yeast strain further includes third and/or fourth gene modifications.

Abstract: Provided is a yeast strain capable of excessively synthesizing cAMP and its construction method and fermentation technique thereof, and application in the field of medicine, animal husbandry, food or chemical industry. The yeast strain includes first and second gene modifications, wherein the first gene includes protein kinase A (PKA) catalytic subunit encoding genes TPK1, TPK2 and TPK3, by modifying the first gene, the activity or expression of PKA is completely inhibited, so that feedback inhibition to cyclic adenosine monophosphate (cAMP) is eliminated, but at the same time, the growth of the yeast is inhibited; and the second gene modification eliminates growth inhibition caused by the first gene modification, so that the yeast grows normally, and the cAMP yield by the yeast is increased, wherein the increase of the cAMP yield is relative to the cAMP yield by an unmodified yeast. The yeast strain further includes third and/or fourth gene modifications.