S31: A Brief History of Cargill Commercial Lactic Acid Production

Scaling an industrial fermentation is often presented as a linear process with success achieved when the industrial scale tanks are reached, when in fact that is often when the true challenges began. Multiple iterations of scale-up and scale-down are often required to yield a stable, high yield, economically viable fermentation. All parts of the process from media, process conditions and strain must be fluid and adapt to changing economics. Stability of strain is often under-rated when developing bioprocesses, as this can be hard to test at the lab scale. Assumptions made at the lab scale regarding strain stability and perceived challenges in scale-up are often inaccurate vs. those actually encountered at the production scale. Even given that lactic acid is one of the oldest chemicals produced through fermentation with a vast literature and practical knowledge base, a series of challenges were encountered when scaling this fermentation. Issues and mitigation strategies will be discussed for contamination, phage, by-products and raw material cost spikes.  Solutions for these problems span the range from very traditional fermentation condition manipulation to cutting edge biotechnology solutions.