Ecological Stoichiometry: Liebig's Minimum
Droop model: cell quota dynamics, dual nutrient co-limitation, chemostat growth
Droop Model (dual nutrient): dQN/dt = ρN(N/(kN+N)) − μ·QN; dQP/dt = ρP(P/(kP+P)) − μ·QP.
μ = μmax·min(1−QNmin/QN, 1−QPmin/QP) [Liebig + Droop].
dN/dt = D(SN−N) − ρN·X·N/(kN+N); dX/dt = (μ−D)X.
The limiting nutrient switches depending on supply ratio vs Redfield ratio (N:P≈16:1).