Minimal medium consisting of 5 g glucose per liter, 48 mM Na2HPO4,22mMKH2PO4, 10 mM NaCl, and40 mM (NH4)SO4, was used. For minimal medium, the following components were filter-sterilized separately and then added (per liter of final volume): 1 ml 1 M MgSO4, 1 ml 0.1 mM CaCl2, 1ml vitamin B1 (1 mg/l stock) and 10 ml trace element solution containing (per liter): 0.55 g CaCl2, 1 g FeCl3, 0.1 g MnCl2·4H2O, 0.17 g ZnCl2, 0.043 g CuCl2·2H2O, 0.06 g CoCl2·2H2O, and 0.06 g Na2MoO4·2H2O.

The isotopomer balance systems were described using isotopomer mapping matrices [1] and solved through an iterative scheme, based on the approach of [1]. The isotopomers of the proteinogenic amino acids were used to generate NMR synthetic patterns. For the representation of ... the metabolic fluxes, the forward v and backward v fluxes associated with each bidirectional reaction step were transformed into a net v [2]. A non-linear mapping from exchange fluxes to exchange coefficients v exch[0,1] was made to overcome the numerical problems arising from very large parameters values [3]. Please see more details in the original publication. -----------------------------------References------------------------------
[1] Schmidt K, Carlsen M, Nielsen J, Villadsen J (1997). Biotechnol Bioeng 55:831–840. http://doi.org/dfb3d5
[2] Schmidt K, Nielsen J, Villadsen J (1999). J Biotechnol 71:175–190. http://doi.org/bjxbj5 [3] Wiechert W, Siefke C, de Graff AA, Marx A (1997). Biotechnol Bioeng 55:118–135. http://doi.org/fn584s