A seminar at UCSD, presented by Joule, presents a systems approach to helioculture which utilizes organism engineering, reactor design, and helioculture processing towards the production of a desired product.
Beginning with organism engineering, this starts with finding an organism which will be optimal for the process. Joule presents cyanobacterium as the ideal production system, given their unique set of properties vital to efficient bioreactor and process design, such as the ability to integrate foreign DNA, tolerance of brackish water, rapid metabolism, and no biofilm production of biofouling.
The next key step is to optimize the metabolic fluxes through desired pathways, and minimize or eliminate nonessential pathways. This is performed through a series of knockouts and knockins in order to divert the core metabolism to productive pathways which will produce the desired product. This metabolic engineering is one of the most important parts of the process, as it dictates reactor and process design, given that it determines what and how the product is output, the quantities, and the timeframe. This technology has been pioneered by other companies, most recently, and with a recent IPO, Genomatica.
Genomatica begun out of the Palsson lab at UCSD with the goal of creating biofuels and industrial precursors and materials. The company has also utilized metabolic engineering to much success, earning investor trust and raising $15M in Series C funding in April of 2010 and recently $45M in March of 2011.
The key difference between these two technologies is in the energy input – while Genomatica utilizes common energy inputs such as basic sugars, Joule utilizes heliocultures, which derive much of their energy from the sun, even stating that 95% of the sun’s energy is diverted to growth. Theoretically, Joule is poised to have a significant advantage over Genomatica, given that the sun’s energy is a free resource, only demanding in physical space accessible to sunlight or to electrically powered means.
However, Joule faces significant challenges – historically, photon conversion and carbon fixation is mismatched in heliocultures, meaning effectively reduced efficiency, and introducing higher costs and lower returns. Not only that, but these photosynthetic mechanisms can cause damage to the organisms, requiring continual, higher maintenance of the system. Joule combats these problems by utilizing light dark cycling, the introduction of enzymatic means to reduce free radical damage, and metabolic engineering to concentrate CO2, but it remains to be seen how successful heliocultures are. Nonetheless, investors have hope, as Joule recently raised $30M in Series B funding in April of 2010.
Genomatica’s recent IPO and Joule’s recent successes show that the field of metabolic engineering in biotechnology is ripe for startups with innovative process design and goals. Alternative fuels are the focus of these companies at the moment, and given the economic context of the times today, with crude oil reaching over $100 a barrel, there has been no better time to invest in alternative fuel processes.
