Abstract. Membrane systems are gaining a prominent role in the modeling of biochemical processes and cellular dynamics. We associate specific reactivity values to the production rules in a way to be able to tune their rewriting activity, according to the kinetic and state-dependent parameters of the physical system. We come up with an algorithm that exhibits a good degree of versatility, meanwhile it gives an answer to the problem of representing oscillatory biological and biochemical phenomena, so far mostly treated with differential mathematical tools, by means of symbolic rewriting. Results from simulations of the Lotka-Volterra’s predator-prey population dynamics envision application of this algorithm in biochemical dynamics of interest.