发酵液中乳酸的盐析萃取

Salting-out Extraction of Lactic Acid from Fermentation Broth

研究了一种利用盐析萃取法分离发酵液中乳酸的新方法.通过系统考察乳酸在不同盐析萃取体系中的分配规律,发现K2HPO4-甲醇和K2HPO4-乙醇体系适合分离发酵液中的乳酸.发酵液中乳酸浓度为167g/L时,采用25%(ω)K2HPO4-26%(ω)甲醇盐析萃取体系,乳酸的分配系数和回收率分别为4.01和86.0%;采用14%(ω)K2HPO4-30%(ω)乙醇盐析萃取体系,乳酸的分配系数和回收率分别为3.23和90.6%.此时上相中残余葡萄糖、菌体和可溶性蛋白的去除率分别达67.3%,100%和85.9%.

Salting-out extraction was used for recovery of lactic acid from fermentation broth. The different hydrophilic organic solvents-inorganic salts systems were investigated for their extraction ability. The results showed that the K2HPO4-methanol and K2HPO4-ethanol systems appeared to be favorable. The partition coefficient and recovery rate of lactic acid reached up to 4：01 and 86.0% for the system of 25%（ω） K2HPO4-26%（ω） methanol, when the concentration of lactic acid was 167 g/L in the broth. For the system of 14%（ω） K2HPO4-30%（ω） ethanol, the partition coefficient and recovery rate of lactic acid reached up to 3.23 and 90.6%. The removal rate of glucose, cells and proteins reached 67.3%, 100% and 85.9%, respectively.