Dynamics Of Protist, Bacteria And Organic Matter System

The action of bacteria decomposing organic matter and protist grazing on bacteria is an important link in the food chain in nature. Protist grazing on bacteria increases the de-composition of organic matter. This paper establishes a mathematical model about protist, bacteria and organic matter using Stoichiometry in the model to explain the phenomenon. It researches the model through qualitative analysis. First, this paper analyzes the existence and the stability of equilibrium points in bacteria and organic matter dynamics.then analyzes the existence and the stability of boundary equilibriums in protist, bacteria and organic matter dy-namics and demonstrates the sufficient conditions of the existence of positive equilibrium and the sufficient conditions of local asymptotic stability. The conclusion is that protist grazing on bacteria increases the decomposition of organic matter. Protist.,bacteria and organic matter could coexist.