超滤-醇沉法从发酵液中提取1,3-丙二醇

介绍了超滤-醇沉法从发酵液中提取1,3-丙二醇的工艺. 首先通过超滤，菌体、蛋白质与核酸的去除率分别为99%, 89.4%和69%，然后减压蒸馏浓缩发酵液，最后醇沉浓缩发酵液，使核酸、多糖、蛋白质等生物大分子沉淀析出，乙醇加入量与浓缩发酵液的最佳体积比为2:1. 粗产品中总蛋白和核酸与发酵液相比分别减少了97.4%和89.7%，溶液电导率下降了95.8%. 考察了浓缩发酵液的含水量、pH值对醇沉效果的影响及醇沉对发酵液中蛋白质、核酸、盐类的去除效果. 实验发现，浓缩液含水量越低，醇沉效果越好，浓缩发酵液含水量为1%时，杂质去除率达90%以上. 浓缩发酵液pH值的变化对醇沉杂质的影响较大，强碱和强酸条件下可沉淀出大量杂质.

Separation of 1,3-Propanediol from Fermentative Broth by Combination of Ultrafiltration and Alcohol Precipitation

The separation of 1,3-propanediol from fermentative broth by a combination of ultrafiltration and alcohol precipitation was well investigated. The broth was firstly filtered by ultrafiltration,and 99% of cell,89.4% of protein,and 69% of nucleic acid could be removed. The obtained broth was further condensed by vacuum distillation and alcohol was added. Then,the macromolecular impurities,such as nucleic acids,polysaccharides and proteins,as well as small molecules (inorganic and organic salts) precipitated. The optimal volume ratio of alcohol added to condensed fermentation broth was determined to be 2:1. As a result,protein,nucleic acid and conductivity decreased by 97.4%,89.7%,and 95.8% respectively. The influences of pH and water content in condensed broth on alcohol precipitation were also investigated. It can be found that the lower the water content,the more the impurity removed. 90% of impurities were removed when water content was 1%. The pH value of broth had great effect on precipitation,most impurity precipitated under strong acid or alkaline condition.