Table II. Biomass composition used in the model.

Fractional composition was adopted from the Synechocystis sp. PCC 6803 model developed by Nogales et al. (2012) and Knoop et al. (2013). The definition and the reaction formula of the different fractions were adapted for Anabaena sp. PCC 7120, wherever specific analysis data were available.

Fraction	Source of Data and Reference
Pigments	Analysis of carotenoid composition (Takaichi et al., 2005; Takaichi and Mochimaru, 2007; Mochimaru et al., 2008; Graham and Bryant, 2009)
DNA	Base abundance calculated from the genome sequence (Kaneko et al., 2001)
RNA	Base abundance calculated for annotated genes and weighted by RNAseq abundance (Kaneko et al., 2001; Flaherty et al., 2011)
Proteins	Amino acid abundance calculated and weighted by RNAseq abundance (Kaneko et al., 2001; Flaherty et al., 2011)
Lipids	Adopted from Synechocystis sp. PCC 6803 (Nogales et al., 2012; Knoop et al., 2013)
Cell wall	Adopted from Synechocystis sp. PCC 6803
Inorganic ions	Adopted from Synechocystis sp. PCC 6803
Pool fraction	Adopted from Synechocystis sp. PCC 6803a

^aNo genes could be identified for the biosynthesis of spermidine (Jantaro et al., 2003; Incharoensakdi et al., 2010).