Biosurfactants are difficult to produce in an economic manner for several reasons: 1. Overproducing strains of bacteria are rare and those found generally display a very low productivity. In addition complex media need to be applied. 2. The regulation of biosurfactant synthesis is hardly understood, seeminly it represents a "secondary metabolite" regulation. Among others O2-limitation has been described as an essential parameter to govern biosurfactant production. 3. An improvement of the production yield is hampered by the strong foam formation. Consequently diluted media have to be applied and only immobilized systems provided an increased productivity of about 3 g l-1 h-1. In the following improved cultivation methods with developed defined media are described leading to enhanced productivities with the potential of 5 to 10 g l-1 h-1 upon optimization of the bleeding rate of an integrated continuous process. Instead of indirect product analytics by physical methods (CMC, surface tension) HPLC analysis for a new biosurfactant has been developed.
