FedBatchDesigner
A user-friendly dashboard for modeling and optimizing growth-arrested fed-batch processes
Published by ACS Synthetic Biology. 15 August 2025; 14 (8): 3252–3257.
Developed by Andrea C. Graf, Julian Libiseller-Egger, Mathias Gotsmy, and Jürgen Zanghellini
The aim of the web tool FedBatchDesigner is to explore the design space of fed-batch fermentations with a growth-arrested second stage. The feed profile of the first stage is either exponential or constant, while the feed rate is kept constant during the second stage (at a value determined by the maintenance coefficient ρ and growth-independent production rate π0).
The tunable variables for the process design are:
- The feed rate (F for constant feed) or specific growth rate (μ for exponential feed) during the first stage.
- The point of switching between the first and second stage (tswitch) or, more practically, the fraction of the total feed volume that is fed during the first stage (Vfrac=Vs1/Vtot).
FedBatchDesigner: Concentration profiles were calculated for different values of F (the constant feed rate during the growth stage) and the fraction of the total feed volume fed during the growth stage (i.e. before t_switch).
Outputs include visualizations of how the average volumetric productivity (also called space-time yield) and the final product titer relate to these parameters. Thanks to analytical solutions for the calculation of biomass and product formation in the first stage, the whole design space can be evaluated with a brute force approach in little time. The assumptions that those analytical formulas rely upon are usually satisfied in microbial fed-batch settings (for details on assumptions see below).
One crucial aspect to note is that we assume no growth in the second stage with the feed rate held constant at the exact value that satisfies the substrate requirements for maintenance and product formation (i.e. the best-case scenario).
