Understanding the behaviour of micro-organisms in a fluid environment is key to many new technologies in the areas of energy harvesting, CO2 sequestration, biofuel production and novel drug discovery. For instance, algae within a bioreactor can either be used to consume CO2 from an external source or in the production of biofuels and other useful by-products. In producing high-throughput systems the behaviour of the algae and the concentrations of important chemical compounds within a flowing fluid is crucial. This project considers a new mathematical model of such systems, based on a theoretical description first proposed at Strathclyde over 40 years ago as well as a successful ongoing research project, which aims to incorporates the flow, mixing and organisation of the algal components, as well as the advection and diffusion of key chemical compounds. A better understanding of such flows will enable the optimisation of such systems. The key aims of the project are to produce a realistic quantitative mathematical model of mixing within these systems, since this will influence the efficiency of the use of resource (i.e. energy source or CO2 concentration), and to use this to model typical bioreactor systems in order to deliver performance predictions for novel bioreactors.