【Abstract】 This work proposes an improved process technology of L(+)\|tartaric acid produced by using cis\|epoxysuccinates as the substrate for fermentation.The key to the question is to apply dipotassium cis\|epoxysuccinate as the substrate instead of disodium cis\|epoxysuccinate.As compared with the original process technology,the improved one has prominent advantages:1.High yield of acid, increased by 20%～30% over the old one;2.High rate of recovery,from about 60% to 80%;3.One of the raw materials is cheaper,the KOH is expensive than NaOH,but half of the K kions could be used cyclically,and the varied products could be obtained easily;4.The tough working procedure of filtration of fermented liquor could be evaded,the total working procedures might increase to some extent,but the cost of production will be reduced obviously,it is advantageous to industrial production.更多还原