The pattern of the biomass specific growth rate is an important focus for many biotechnological applications. Several control strategies have been employed to describe version of the exponential phase of growth of microorganisms. Moreover, in some bioprocesses there is more than one feeding substrates required for the specific growth. Hence, the problem of estimating multiple substrate consumption rates together with the specific growth rate of the microorganism becomes applicable. In this context, the dynamics behaviour of fed-batch process with multiple substrates (dextrose and peptone) and kinetics is further investigated in Beauveria bassiana. Different features of the proposed model are assessed by numerical simulation in different scenarios.