Parameter justification for bacarena

[hites77]

Hi, I have couple of question on some of the usefullness of the bacarena parameter:

1. secondary objective - there is sec_obj parameter, which can be set to mtf, opt_rxn, opt_ex, sumex. Can you let me know in what condition we can use it and what changes it will do to the simulation study? Because primary objective is biomass growth, so where to define the secondary objective, lets say production of some specific metabolites.
2. About stir parameter. As it is off by default, so in what condition it should be set to true and can its time or speed be also adjusted if it really simulate a flask condition of microbial growth ?