Ochsner U A, Hembach T, Fiechter A
Institute for Biotechnology, Swiss Federal Institute of Technology, ETH-Hönggerberg, Zürich, Switzerland.
Adv Biochem Eng Biotechnol. 1996;53:89-118. doi: 10.1007/BFb0102326.
Biosurfactants are of increasing interest due to their broad range of potential applications. A large variety of microbial surfactants is known at present, some of which may be used for specific applications. Towards the large scale industrial production of biosurfactants, the physiology, biochemistry and genetics of biosurfactant synthesis has to be well understood. A fully integrated process has to be developed, allowing high productivities under optimized conditions. In the past few years, we have investigated the molecular biology of rhamnolipid biosynthesis have been partially purified and characterized. The structural and regulatory genes encoding the rhamnolipid synthesis pathway have been isolated and characterized. The knowledge of the complex mechanisms involved in rhamnolipid synthesis facilitates the overproduction of these extracellular compounds. Furthermore, the transfer of the relevant genes into other species allows the production of rhamnolipids in heterologous hosts under controlled conditions. An integrated process for the production of rhamnolipids on an industrial scale has been developed. This process involves continuous cultivation under optimized media and growth conditions and makes use of refined methods of cell recycling, gas exchange and downstream processing, thus allowing high yields and productivities.
由于生物表面活性剂具有广泛的潜在应用，因此其受到越来越多的关注。目前已知有大量的微生物表面活性剂，其中一些可用于特定应用。为了实现生物表面活性剂的大规模工业生产，必须充分了解生物表面活性剂合成的生理学、生物化学和遗传学。必须开发一个完全集成的工艺，以便在优化条件下实现高生产率。在过去几年中，我们研究了鼠李糖脂生物合成的分子生物学，鼠李糖脂已被部分纯化和表征。编码鼠李糖脂合成途径的结构和调控基因已被分离和表征。对鼠李糖脂合成所涉及的复杂机制的了解有助于这些细胞外化合物的过量生产。此外，将相关基因转移到其他物种中可以在可控条件下在异源宿主中生产鼠李糖脂。已经开发出一种工业规模生产鼠李糖脂的集成工艺。该工艺包括在优化的培养基和生长条件下进行连续培养，并利用精细的细胞循环、气体交换和下游加工方法，从而实现高产量和高生产率。
