From the beginning, our goal was to find a way to dye jeans that could eventually replace the unsustainable industrial process used today. To make sure that the individual unit operations in our process were compatible with scalable design principles, the UC Berkeley iGEM team consulted experts at the Advanced Biofuels Process Demonstration Unit (ABPDU) located in Emeryville, California. The ABPDU is a facility affiliated with the Lawrence Berkeley National Laboratory, and it is designed to help transform laboratory-scale operations into larger, economically feasible processes. At the ABPDU we talked to Dr. Julio Baez, the program manager of the facility and gained insight into factors that affect scale up.
From our interview and tour of ABPDU with Dr. Baez, we learned that a problem which arises when using large bioreactors is supplying enough oxygen to the cells in anaerobic processes. Thus, executing biological processes under anaerobic conditions allows for a larger scale which in turn can lower fermentation costs.
Lysing and purifying cells to obtain a product are typically expensive steps that add to the cost of our final product. As we learned from our interview with the CEO of Lumi, in order to compete with established industries, our product must be the same price or cheaper. Thus, if we can reduce costs by secreting our product and avoiding these steps, we subsequently lower the barriers to entry into the denim dyeing industry.
During our tour at ABPDU, we saw several reactors to perform pretreatment of biomass such as grass, wood, and agricultural residues. Pretreatment of biomass breaks down the “shields” formed by ligin and hemicellulose, thus reducing the degree of polymerization to facilitate rapid and efficient downstream processes. Next to the reactors for pretreament of biomass, we saw small reactors used for enzymatic saccharification. Saccharification is the process of making sugar from starch reserves.
Needless to say, the UC Berkeley iGEM team was soon then awestruck to see ABPDU’s bioreactors, which have the capacity to grow bacteria, fungi, and yeast up to 300-liters. The bioreactors were equipped with advanced control systems for pH, temperature, dissolved oxygen and other process conditions.
Finally, the team was quite happy to see some familiar equipment for enzyme purification at ABPDU, such as a high-throughput centrifuge, a large column chromatography system for enzyme separation and purification, and protein analysis equipments such as the HPLC and gas mass spectroscopy.
From this educational field trip to ABPDU, we learned how the facility provided material and energy balance data to help develop parameters for expansion from pilot to commercial scale production
In order for the scale up of our process to be successful, we need to optimize our process and reduce costs as much as possible. We learned that anaerobic conditions can lower operating costs, and secretion can reduce process cost. Consequently, we applied these principles to engineer a cost effective system. Check out our result in the next section! Also, here is our interview with experts in the dyeing industry!
*The UC Berkeley iGEM team would like to thank Dr. Julio A. Baez for the wonderful and detailed tour of the Advanced Biofuels Process Demonstration Unit (ABPDU).
- "Berkeley Lab Opens Advanced Biofuels Facility « Berkeley Lab News Center." Berkeley Lab News Center RSS. N.p., n.d. Web. 22 Sept. 2013.
- Yamashita, Y., Sasaki, C., & Nakamura, Y. (2010). Effective enzyme saccharification and ethanol production from Japanese cedar using various pretreatment methods. Journal of Bioscience and Bioengineering, 110, 79–86.
- Zheng, Y., Pan, Z., & Zhang, R. (2009). Overview of biomass pretreatment for cellulosic ethanol production. International Journal, 2, 51–68. doi:10.3965/j.issn.1934-6344.2009.03.051-068