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1990
Conference Paper
Titel
Coupling of production and downstream processing in the continuous rhamnolipid fermentation
Alternative
Verbindung von Produktion und Downstream Processing in der kontinuierlichen Rhamnolipid-Fermentation
Abstract
A new process for the continuous aerobic production of rhamnolipids by Pseudomonas aeruginosa DSM 2659 is presented. Two membrane steps are integrated in this process, one for cell recycle and product stream preparation and the other for oxygenation and carbon dioxide removal. The direct integration of separation and purification steps into the bioreactor is a tool to enhance the productivity of the fermenter and the efficiency of subsequent downstream processing. The comparison of this process with a chemostat shows, that both the specific productivity and the product yield could be enhanced. The productivity of the reactor was improved by a factor of approximately 6 to 545 mgl high -1 h high -1. The combination of filtration and foam fractionation reduced the volume of the reactor effluent which has to be processed by downstream processing up to 90% with a high product recovery of about 98%. Therefore the required quantity of chemicals and the scale of the subsequent product purifica tion, extraction or precipitation could be tremendously reduced. By using membranes for aeration and carbon dioxide removal, the problem of the formation of stable foams in fermentation is solved and it is now possible to handle high surfactant concentrations in an aerobic microbial production without adding antifoam agent.