This paper deals with the dynamical modelling, the control and the state observability analysis of distributed parameter fixed bed reactors. The first objective is to propose control algorithms for fixed bed bioreactors which are based on the nonlinear distributed parameter model of the process. The central question we address in this part of the paper is how to extend the application of adaptive linearizing control schemes to nonlinear distributed parameter bioprocesses. A second objective of this paper is to consider state observation : we analyze the influence of the position of the "internal" sensor(s) on the observability in order to determine the best observability possible in practice. The criterion is the condition number of the observability matrix of the linearized tangent model of the discretized model of the process. It is shown that there is an optimal sensor location for which the condition number is minimized.