6 th DEB Course LISBOA 4 12 April

6 th DEB Course LISBOA, 4 -12 April MULTIVARIATE DEB MODELS GENERALIZATION OF THE STANDARDDEB MODEL FOR MULTIPLE STATE VARIABLES Gonçalo Marques Instituto Superior Técnico, goncalo. marques@ist. utl. pt Instituto Superior Técnico Departamento de Engenharia Mecânica - Secção de Energia e Ambiente 4 -12 April 2011

Summary 2 The standard DEB model is built with one reserve, one structure, one maturity and one reproduction buffer for an organism that feeds on one substrate. There are situations when the standard DEB model is not enough to realistically simulate an organism or a specific feature of an organism. However DEB theory gives us the tools to build models beyond the standard DEB model. The construction of the generalized DEB models will be theme of this presentation. 1. State variables 2. Multiple substrates 3. Multiple reserves 4. Multiple structures 5. Does it make sense to talk about multiple maturities? 6. Multiple products 6 th DEB Course, 4 -12 April 2011

State variables 3 State variables define the state of the system. In the standard DEB model the system organism-environment is defined by: Organism – reserve, structure, maturity, reproduction buffer Environment – substrate 6 th DEB Course, 4 -12 April 2011

State variables 4 Substrate – compound assimilated by an organism Reserve – assimilation is stocked in the reserve. The output of the reserve (mobilization flux) will be used for every metabolic purpose. Structure – it is linked to size, and therefore it affects assimilation. It needs to be maintained. Maturity – it is a measure of the complexity of the organism. It also needs to be maintained. Product – compound produced by the organism. It could be released into the environment or remain attached to the organism. Either way it doesn’t need maintenance. 6 th DEB Course, 4 -12 April 2011

Multiple state variables 5 When we need to add state variables always ask these questions: - Does it comply with the DEB core? - In what situation do I recover the standard DEB model? And does it make sense? - Is this the minimum number of state variables I need to model the feature/behavior/metabolism I want? 6 th DEB Course, 4 -12 April 2011

Multiple substrates 6 First let us look at what is happening with one substrate: b p 6 th DEB Course, 4 -12 April 2011

Multiple substrates 7 6 th DEB Course, 4 -12 April 2011

Multiple reserves 8 There are cases when the organism accumulates different nutrients and there is a need for multiple reserves. But first let us zoom on growth: 6 th DEB Course, 4 -12 April 2011

Multiple reserves 9 There are cases when the organism accumulates different nutrients and there is a need for multiple reserves. But first let us zoom on growth: 6 th DEB Course, 4 -12 April 2011

Multiple reserves 10 First challenge: Computation of the mobilization fluxes 6 th DEB Course, 4 -12 April 2011

Multiple reserves 11 Second challenge: Rejection fluxes 6 th DEB Course, 4 -12 April 2011

Multiple reserves 12 N Multiple limitation The case of a 3 reserve (C, N, P) model for microalgae. P C Lorena (2008) 6 th DEB Course, 4 -12 April 2011

Multiple structures 13 In cases where it is important to model an organ that doesn’t grow proportional to the rest of the body (changes to morphity), it may be needed to add a new structure. 6 th DEB Course, 4 -12 April 2011

Multiple structures 14 Reserves Static 1 set Structures Uptake kappas Constant 6 th DEB Course, 4 -12 April 2011

Multiple structures 15 Reserves Static Uptake kappas Constant 1 set Dynamic Structures Dependent on uptake 6 th DEB Course, 4 -12 April 2011

Multiple structures 16 Reserves Structures Uptake kappas Static Constant 1 set Dependent on uptake Dynamic Plant (Symbiosis) m sets Independent uptakes Constant 6 th DEB Course, 4 -12 April 2011

Multiple modules 17 6 th DEB Course, 4 -12 April 2011

Multiple modules 18 Examples of building blocks: December 1 -3, 2010

Multiple modules 19 6 th DEB Course, 4 -12 April 2011

Multiple maturities 20 Does it make sense to talk about multiple maturities? I’m not aware of any simulation made with multiple maturities, but it could make sense. Regrowth of a chestnut tree 6 th DEB Course, 4 -12 April 2011

Multiple products 21 Does it make sense to use more fluxes for product formation? 6 th DEB Course, 4 -12 April 2011