Electronic Thesis and Dissertation Repository


Master of Engineering Science


Chemical and Biochemical Engineering


Dr. Wankei Wan


Biopolymers and other naturally derived chemicals continue to gain attention over petrochemical based products due to the price volatility of crude oil, increasing need to reduce greenhouse gas emissions and public awareness of environmental issues. Cyanobacterium Spirulina (Arthrospira) platensis, a commercially feasible blue-green alga, is able to synthesize poly(3-hydroxybutyrate) (PHB), a biodegradable and biocompatible polymer, as an energy storage product of photosynthesis directly from CO2. A flat plate photobioreactor (PBR) with LED illumination was designed for the cultivation of S. platensis. Computational fluid dynamics (CFD) software was used to improve airflow uniformity and mixing in the photobioreactor. PHB extracted from S. platensis biomass was characterized and compared to commercially available PHB produced by microbial fermentation. PHB of high purity was obtained with crystallinity lower than that of commercial PHB. Improved polymer properties, such as reduced brittleness due to a lower crystallinity, could further increase the range of applications of PHB.