Computational power of cell separation in tissue P systems

The paper focuses on the relation between biological and computational information processing. Several simple biological operations, as the exchange of molecules via cellular membrane or the cellular growth and separation, are abstracted into a mathematical model called membrane system (P system). This paper studies tissue P systems where a fixed interaction graph defines the communication between various types of cells. Polynomially uniform families of tissue P systems with the operation of cell separation were recently studied. Their computational power in polynomial time was shown to range between P and NP ∪ co - NP , characterizing borderlines between tractability and intractability by the length of rules controlling the interchange of objects. Here, we show that the computational power of these uniform families is limited by the class PSPACE , which is the class characterizing the power of classical parallel computing models, such as PRAM or the alternating Turing machine.