The MELISSA project of ESA constitutes a test bench for the research and development of a biological life support system. The objectives of simulation and control for the MELISSA project, require to establish knowledge models on each compartment of this artificial ecosystem. Previous research allowed to develop and successfully apply a mathematical model, describing light transfer inside biological media and its coupling with growth kinetics, to the photoautotroph cyanobacterium, used in compartment IV, Spirulina platensis using photoreactors of different geometry. This paper reports on the extension of the previously developed model for its application to the photoheterotrophic bacterium Rhodospirillum rubrum. For this purpose the main differences among those two different micro-organisms, namely the size of the specimen, the wavelength of light absorption and different metabolic capabilities, have been taken into account. The adapted model for Rhadospirillum rubrum is proposed. A new method to determine the required light transfer parameters is proposed and applied. Independent experiments are performed to assess the kinetic parameters. The new model parameters are employed for the computer simulations and the simulated data are compared with the experimental data. The results demonstrate that the modified model can be successfully applied to the description of the kinetic behaviour of the compartment II of the MELISSA loop. The range of conditions for model application, the required experiments to expand the applicability of the model to different types of vessel geometry and to different culture conditions is also discussed.
|Journal||European Space Agency, (Special Publication) ESA SP|
|Issue number||400 PART 2|
|Publication status||Published - 1 Dec 1997|