Variety of control schemes
Culture offers a variety of feed control schemes. These include standard pre-defined timed feed regimes with fixed, linear and exponential feed rates. Feeds can be programmed with automated feed triggers to initiate feeds upon completion of carbon in the main batch phase. Culture also offers a variety of dynamic feeds including pH-stat, DO-stat, and various pulse feed strategies. As each reactor is outfitted with continuous off-gas measurements, a number of dynamic methods based on these measurements are also available, including OUR-stat, CER-stat and RQ-stat. Methods can be developed on demand.
Precision feed control
Each of Culture’s bioreactors has up to 5 separate feeds available. Each of these feeds is delivered via a peristaltic pump with individual scale feedback control. This results in precise weight-based delivery of feeds so that the amount of feed delivered over the course of the fermentation is as intended. The capacity to deliver up to 5 feeds means that schemes with auxiliary feeds can be supported.
Capacity to optimize methods
When developing a feed scheme, some factors may need to be optimized empirically. These include the magnitude of signals used to trigger feeds and trials of the impact of over and underfeeding. Culture’s capacity enables methods to be developed and fine-tuned with a number of different variables.
For more on feed strategies for process development, including key challenges to keep in mind and best practices: