The biomass equation of M. alpina was assumed to have six components: proteins, DNA, RNA, lipids, the cell wall and the small molecule pool [59,60]. Since no detailed information on M. alpina DNA and RNA was available, the ratio was assumed to be the same as in the related Aspergillus niger [61]. The nucleotide and amino acid composition were calculated based on the M. alpina ATCC 32222 genome [2], as no specific experimental data were available. Similarly, the cell wall composition was calculated based on the typical fungal cell wall structure [62]. The lipid composition was calculated based on the current literature [63]. For calculation of energetic parameters, the growth and non-growth associated ATP maintenance values (GAM and NGAM, respectively) were assumed to be the same as those in the central carbon metabolic model of A. niger [64]. Detailed biomass composition information can be found in Additional file 7.