由乳酸铵发酵液提取乳酸的研究

Study on the Process of Separation of Lactic Acid from the Lactic-ammonium Fermentation Broth

对从Lactobacillus lactis BME5-18M发酵生产乳酸的发酵液中提取乳酸的工艺进行了研究.主要考察了乳酸铵发酵液除色素、除蛋白和除盐转酸等对提取过程的影响.确定了最佳的工艺条件:采用粉末状活性炭脱色,用量为发酵液质量的3%,温度为43℃,时间为20min,pH为5.8左右;用超滤法除蛋白,超滤时间为45min,操作压力为200kPa,pH为5左右;采用联合使用强酸性树脂001×7树脂与强碱性树脂201×4进行脱盐转酸,并且先过阳离子交换柱后过阴离子交换柱脱盐效果更好.在最佳条件下乳酸收率可达65.8%.

The process of extraction of lactic acid fermented by Lactobacillus lactis BME5-18M in the fermentation is stu- died. Theprocess of separation concernsthat Lactic-ammonium fermentation is discolored by active carbon, and removed proteins by polysulfone ultrafiltration (UF) membrane, and desalinated and turned lactic acid by ion-exchange resin. So the best technology is concluded as followed: the adsorbent decolorization of fermented broth by dusty active carbon that contained 3% content of fermentation is adsorbent time 20 min, temperature 43 ℃ and pH 5.8. Under the condition of the fermented broth pH 5 and the membrane pressure 200 kPa and UF 45 min, the protein entrapment ratio by polysulf- one ultrafiltration membrane is the best. Anions and cations in the fermentation are removed by 201×4 anion exchange resin and 001×7 cation exchange resin at the desalination technology, and lactic acid is turned by the ion-exchange resin. At the optimum technology, the recovery ratio of lactic acid achieved 65.8%.