(462b) Hands-on Biochemical Production and Process Design

Biochemical production offers a renewable method to generate a variety of small molecules for use as fuels, polymer precursors, scents, flavorings, colors, and pharmaceuticals. However, few processes have made it to full-scale production due to competition with conventional chemical synthesis. We have tasked students to evaluate the economics of scaling up biological production of their choice of three molecules: violacein (a purple dye with antimicrobial properties), psilocybin (a hallucinogen in clinical trials for treatment of depression), or caffeic acid (a nutraceutical with antioxidant properties). This capstone project combines on-paper process design with laboratory-based parameter measurement to offer a hands-on project where students build skills in microbial fermentation, bench-scale purification, and chemical analysis.

Students begin their project by conducting an economic analysis to identify a target market, competing technologies, selling price, and yearly production amount for their molecule of interest. Based on this analysis and a literature review, students create a preliminary process design that meets their specifications (i.e. productivity, purity) as well as identifies key parameters that will influence their scaling. Next, teams enter the laboratory to learn about recombinant bioproduction and to measure the parameters needed for their proposed design. A key aspect of this project is that students grow robust and well-characterized bacterial strains and use known chemical analysis methods. This enhances the feasibility and success of the experiments, especially for students with limited laboratory experience, by largely eliminating unexpected and time-consuming issues associated with cell growth and product analysis. Further, downstream processing through bench-scale drying and extraction experiments are completed to provide yield, stability, and purity process parameters. Finally, the empirical data is combined the original design to create a full process design with scaled unit operations to meet their target market.

Our design project has been offered for the past two years with 18 students participating in groups of 4-5 students in a two-semester capstone design sequence. Through pre- and post-test data we have observed enhanced student learning in microbial fermentation, chemical separations, and molecule analysis techniques. Students are engaged due to it being a hands-on project that combines many topics taught in previous engineering courses to design a process for molecules that benefit society. We have found that this design is highly complementary towards traditional chemical process design and biochemical/bioprocess engineering courses as well as builds on topics covered in separations, kinetics, and material and energy balances. To share this course, select bacterial strains and culture methods will be made available. Student-collected data will also be shared for each biomolecule for fully on-paper design projects.