Biomass Reactions

The biomass reaction is an essential part in Flux Balance Analysis of microbial growth. The composition of the biomass reaction (i.e. stoichiometry of molecular cell constituents) should ideally reflect the molecular makeup of the organism of interest.

Biomass reaction presets

gapseq currently provides three template biomass reactions: One for archaea and two for bacteria (Gram positive and Gram negative).

Bacteria (Gram negative) Bacteria (Gram positive) Archaea
gapseq parameter for draft construction* -b Gram_neg -b Gram_pos -b archaea
Biomass reaction file biommass_Gram_neg.json biommass_Gram_pos.json biommass_archaea.json
Originally derived from:
Reference organism Escherichia coli Bacillus subtilis Methanosarcina barkeri
Reference publication** Orth et al. (2011) Mol Syst Biol Oh et al. (2007) J Biol Chem Feist et al. (2006) Mol Syst Biol
Constituents groups in % (w/w )
DNA 3.1 % 2.60 % 4 %
RNA 20.5 % 6.55 % 24 %
Protein 55 % 52.84 % 63 %
Inorganic compounds 0.5 % 0.50 % -
Co-factors & soluble compounds 3.4 % 4.45 % 4 %
Lipids 9.1 % 7.60 % 4.9 %
Cell wall 8.4 % 25.46 % -
Polysaccharides - - 0.1 %

* If no biomass reaction is defined using this command, gapseq will predict the most likely biomass reaction based on the 16S rRNA gene sequence using a pre-trained classifier.

** When using gapseq for publications, please also cite these original research papers to acknowledge their work. And of course gapseq :)

User-defined biomass reactions

We are currently working on an additional feature to gapseq that allows users to specify biomass reactions that are different from the above mentioned presets. We will describe how to use this feature here as soon as it is implemented.