DYMECOS (DYnamical Microbial and Environmental eCOSystems) is an Inria Associated Team with Chile (2014-2015)
Principal investigator: Alain Rapaport
Principal investigator: Hector Ramirez
Left to right: Alain Rapaport, Hector Ramirez, Pedro Gajardo, Gonzalo Ruiz
Context of the cooperation
Natural or reconstituted microbial ecosystems are often very complex (high diversity, interactions within and between species, coupling with spatial processes: niches, aggregation, biofilm...). We bet that “simple models” (in the sense that they are manageable analytically and in a computer) of these ecosystems can explain their main functions, mainly concerning degradation and conversion, in a decision-making perspective (i.e. bioprocess control) without an exhaustive description of all microbial actors.
Our objectives is then develop, from expert knowledge and experimental observations made by micro-biologists, models that are simple enough to carry out the determination of "control laws", but realistic enough to be validated on real processes. One of the difficulties is to identify the limits of the validity of these models (especially in terms of population size, and of prediction of the coexistence of species). This requires necessarily a proper mathematical analysis, as well as the development of adapted simulation tools.
A recent trend focuses on the enhancement of secondary outputs of bio-processes. This is typically the case of the biogas production in the treatment of anaerobic solid waste-and wastewater. Practitioners look for strategies that drive the systems to a desired target in terms of both the degradation of the organic matter and the biogas production. This naturally leads to optimization problems in terms of design (e.g does a network of interconnected tanks run better than a single one?), and in terms of feedback control of a given process.
Challenge 1: Parsimonious representations of spatial heterogeneity in liquid media for natural and industrial bioprocesses.
In the consideration of large volumes to be treated by bioprocesses (such as lake purification, landfills or micro-algae cultures...), the effects of spatial heterogeneity cannot be neglected when the media are not perfectly mixed. We focus on the modelling with
interconnected compartments along with the following objectives:
The increasing concerns of valorisation of the production of biogas while conducting anaerobic digestion processes to a given target lead to revisit the problems of piloting bioreactors. Instead of the stabilization around a nominal point, we seek for optimal control strategies for maximizing the biogas production during transient or to reach as fast the best nominal set point. More precisely, we investigate: