The objective of this study was to develop a tandem bio- chemical transformation of a feedstock material to value-added products. The chosen example is microbial fermentation of glycerol with subsequent esterification of the intermediate 1,3-propanediol with fatty acids. The use of biphasic aqueous/organic medium for the bi-catalytic system is the key feature of this study. In the first part of this work, batch and continuous fermentations of glycerol by Clostridium Butyricum bacteria were optimized to increase productivity of 1,3-propanediol. In the second part, several catalysts were screened for mono- and biphasic transformation of 1,3- propanediol. It was discovered that enzymes are the most suitable catalysts for the tandem reactions of glycerol to 1,3-propanediol derivatives compared to chemical catalysts. Biphasic enzymatic esterification of 1,3-propanediol was further optimized using Rhizomucor miehei lipase. Finally, a segmented flow tubular reactor and hollow fiber membrane contactors were designed and tested as a concept tandem reactor. The hollow fiber reactor with Rhizomucor miehei lipase immobilized onto polypropylene membrane was found to be the most effective in the biphasic linoleic acid/aqueous esterification of 1,3-propanediol. In general, the demonstrated approach and the developed system can be easily utilized in the biorefinery processes to avoid extraction and purification of the intermediate products, thus reducing time, energy and emissions.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:537264 |
| Date | January 2010 |
| Creators | Sotenko, Maria V. |
| Publisher | University of Warwick |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://wrap.warwick.ac.uk/35606/ |
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