title: Minimal cut sets in a metabolic network are elementary modes in a dual network.
abstract: BACKGROUND
  Elementary modes (EMs) and minimal cut sets (MCSs) provide important techniques for metabolic network modeling. Whereas EMs describe minimal subnetworks that can function in steady state, MCSs are sets of reactions whose removal will disable certain network functions. Effective algorithms were developed for EM computation while calculation of MCSs is typically addressed by indirect methods requiring the computation of EMs as initial step.
  
  
  RESULTS
  In this contribution, we provide a method that determines MCSs directly without calculating the EMs. We introduce a duality framework for metabolic networks where the enumeration of MCSs in the original network is reduced to identifying the EMs in a dual network. As a further extension, we propose a generalization of MCSs in metabolic networks by allowing the combination of inhomogeneous constraints on reaction rates. This framework provides a promising tool to open the concept of EMs and MCSs to a wider class of applications.
  
  
  BACKGROUND
  utz-uwe.haus@math.ethz.ch; klamt@mpi-magdeburg.mpg.de
  
  
  BACKGROUND
  Supplementary data are available at Bioinformatics online.
authors.affiliation: Institute for Operations Research, Department of Mathematics, ETH Zürich, Rämistrasse 101, 8092 Zürich, Switzerland.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Ballerstein
authors.forename: Axel
authors.initials: A
authors.lastname: von Kamp
authors.forename: Steffen
authors.initials: S
authors.lastname: Klamt
authors.forename: Utz-Uwe
authors.initials: UU
authors.lastname: Haus
mesh_terms: D000465:Algorithms; D019295:Computational Biology / Q000379:methods*; D004926:Escherichia coli / Q000378:metabolism*; D053858:Metabolic Networks and Pathways