Metabolic engineering aims at modulating the capabilities of metabolic networks by changing the activity of biochemical reactions. The existing constraint-based approaches for metabolic engineering have proven useful, but are limited only to reactions catalogued in various pathway databases.
Larhlimi, A., Basler, G., Grimbs, S., Selbig, J., & Nikoloski, Z. (2012). Stoichiometric capacitance reveals the theoretical capabilities of metabolic networks. Bioinformatics, 28(18). https://doi.org/10.1093/bioinformatics/bts381