if model.parameters.get(id='K_m_{}_{}'.format(reaction.id, species.species_type.id)):
                        model_Km = model.parameters.get_one(
                            id='K_m_{}_{}'.format(reaction.id, species.species_type.id))
                        if species.distribution_init_concentration.mean:
                            model_Km.value = beta * species.distribution_init_concentration.mean \