TABLE 2.

List of parameters which are optimally determined by numerical simulations

Parameters	Description	Value	Units
ϵ	Ratio of the rate constant of the enzymatic Pel reactions in the culture medium and the buffera	1 or 1/3
k5	Phosphorylation rate of KDG	150	h−1
β1	Maximum rate of synthesis of Pelsb	30	μm h−1
γ	Cell membrane import rate	60	h−1
Kd6	Equilibrium dissociation constant for KdgR2·Pr-pel complexc	4 × 10−3	μm

^a In the simulations ϵ k_cat represents the enzymatic reaction rate, and ϵ is let to vary as a free parameter bounded from above by 1. The k_cat of the five major Pel enzymes had been measured, as reported in Ref. 30, giving an average value of 6 × 10⁴ min⁻¹. As mentioned under “Discussion,” the value ϵ = 1 was found to be fairly good when a large set of polymer degradation reactions was considered (e.g. with maximum polymer length L = 300), whereas ϵ = 1/3 was found to be optimal in the case of L = 2. The latter case corresponds to a simplified model where the enzymatic degradation occurs in a single reaction step.

^b The obtained value of β₁ corresponds to a maximal synthesis rate of five proteins/s/cell (with v_cell = 1 (μm)³). So if mainly five pel genes are involved in this production, the maximal production rate corresponds to 1 protein/s/cell.

^c In Ref. 16, the values for the dissociation constant for KdgR operator of pel genes were measured and found typically between 10⁻³ and 10⁻⁴ μm.