,
Mona Singh
Creative Commons Attribution 4.0 International license
Constraint-based metabolic modeling is the predominant framework for simulating cellular metabolism. The central assumption of these models is that metabolism operates at a steady state, meaning that the production and consumption rates of each metabolite are balanced. This assumption imposes linear constraints on the fluxes of biochemical reactions. Flux Balance Analysis (FBA), a fundamental method in the field, is formulated as an optimization problem maximizing a cellular objective (e.g., growth) over the resulting linear subspace of steady state fluxes. Many other methods in the field are expressed either as a modification to FBA, or use FBA as a black box within an algorithm. Here, we propose a general alternative to optimization called FBApro. For any given vector of reference fluxes, FBApro finds the closest flux vector within the steady-state subspace, and accounts for both partially given reference fluxes and exact constraints on reactions. While FBApro is the solution to a quadratic program, we show that it can be implemented as a single linear operation using orthogonal projections to corresponding affine spaces and sets of linear equations. The overall approach is computationally efficient, does not require a cellular objective, and is easy to implement. We formally derive the closed-form expressions for FBApro and simpler variants, and validate it on both synthetic and real cancer cell line data. Code availability. The code implementing FBApro is available at https://github.com/Singh-Lab/FBApro. All code required to reproduce the figures in the paper is available, although the data used must be sourced separately. The repository also contains toy models and examples.
@InProceedings{bruner_et_al:LIPIcs.WABI.2026.26,
author = {Bruner, Ariel and Singh, Mona},
title = {{FBApro: A Fast, Simple Linear Transformation for Diverse Metabolic Modeling Tasks}},
booktitle = {26th International Conference on Algorithms for Bioinformatics (WABI 2026)},
pages = {26:1--26:22},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-446-8},
ISSN = {1868-8969},
year = {2026},
volume = {390},
editor = {El-Mabrouk, Nadia and Vandin, Fabio},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.WABI.2026.26},
URN = {urn:nbn:de:0030-drops-275305},
doi = {10.4230/LIPIcs.WABI.2026.26},
annote = {Keywords: metabolic modeling, flux balance analysis, constraint-based metabolic modeling}
}
archived version
archived version