Process for the synthesis of 1,4-butanediol comprising fermentation of a culture medium by a microorganism provided with at least one metabolic pathway for the synthesis of 1,4-butanediol and able to use saccharose, in which said culture medium comprises a glucose and saccharose mixture comprising, based on the combined weight of glucose and saccharose, 10-90% by weight of saccharose and 10-90% by weight of glucose.