Abstract:

A new process for the pretreatment of fermentation broth and the separation of sophorolipids in the industrial production process of sophorolipids (SLs) was optimized. The natural sedimentation method was used instead of the traditional ethyl acetate extraction method to obtain the lactonic sophorolipid from the lower fermentation broth. For the upper fermentation broth, the industrial common-used frame filtering was adopted to replace the traditional laboratory centrifugation method to remove biomass. Methods of resin adsorption and ultrafiltration were selected instead of the organic solvent extraction method and alcohol precipitation method to depigmentation, desalting, and deproteinization. Following this procedure, acidic sophorolipid with high purity was obtained from the upper fermentation broth. The sophorolipids content and composition were determined by HPLC, and it was found that the obtained sophorolipid products met the market standards and performed better than commercial sophorolipids. Hence, this pretreatment and separation process can not only enrich the varieties of sophorolipid products,but also can fill in the defects that the commercial products are a complex mixture of lactonic and acidic sophorolipids. Furthermore, the significantly reduced use of organic reagents during this process makes great improvements in the safety and feasibility of sophorolipid production.

Key words: sophorolipid, separation, sedimentation, filtration, adsorption, ultrafiltration

摘要：

优化确定了槐糖脂（sophorolipids，SLs）的工业化生产过程中发酵液预处理及槐糖脂的分离纯化新工艺。对下层发酵液利用自然沉降法替代传统乙酸乙酯萃取法获得内酯型槐糖脂；对上层发酵液利用工业化生产中常用的板框过滤替代传统实验室离心法去除菌丝体，利用树脂吸附及超滤法除杂替代实验室及生产中常用的有机溶剂萃取法及醇沉法，获得高纯度的酸型槐糖脂产品。通过上述步骤的实施，实现了菌液的有效分离，成功获得了高浓度、高纯度的不同结构的槐糖脂产品。所得产品经槐糖脂含量测定及HPLC组成测定检验发现，产品标准达到市售标准，产品质量优于市售产品。该预处理及分离纯化工艺不仅丰富了槐糖脂类产品的品种，填补了市售产品均为内酯型和酸型槐糖脂混合物的缺陷，还可以减少有机试剂的使用量，提高槐糖脂生产的安全性与可行性，具有重要的生产指导意义，有望产生巨大经济价值。

关键词: 槐糖脂, 分离, 沉降, 过滤, 吸附, 超滤