Avoiding mass transport limitations in hydrophobic biotransformations by efficient cell localization

BIOT 70

Dennis D Yancey Jr., ddyancey@stanford.edu, Channing R Robertson, chanbo@chemeng.stanford.edu, and James Swartz, swartz@chem.stanford.edu. Department of Chemical Engineering, Stanford University, Stanford, CA 94305
Based on microscopy examination, a critical problem with oil:water biotransformations is that the cells aggregate and randomly disperse in both the organic and aqueous bulk phases rather than at their interphase. This dispersion characteristic suggests that the biotransformation rate is limited by the mass transport of the substrate to the biocatalyst. Resolution of this cell dispersion/mass transport problem is initially achieved by manipulating the fermentation media composition. This approach produced cells that efficiently dispersed to the organic water interface in a monolayer, thus increasing the effective biotransformation rate of the system. However, this approach led to cell growth deficiencies. An alternative solution to the problem is to genetically alter the organism to control surface properties that cause aggregation, regardless of the fermentation media composition.
 

Upstream Processing: Biocatalysis
8:00 AM-11:00 AM, Monday, 11 September 2006 Hilton San Francisco -- Imperial A Ballroom, Oral

Division of Biochemical Technology

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006