MODELING THE ALCOHOLIC FERMENTATION OF XYLOSE BY PICHIA-STIPITIS USING A QUALITATIVE REASONING APPROACH

Qualitative Reasoning is a set of Artificial Intelligence theories, me thods, and techniques that provide an answer to modeling problems in d omains in which one can have a clear notion of how a system is functio ning without being able to express it as classical mathematical equati ons, and where is posed the problem of using jointly quantitative and qualitative data, as well as processing a big amount of complex knowle dge. SIMAO ('a System to Interpret Measurements And Observations') is an attempt to deal with such problems. Although primarily devised for heterogeneous data interpretation in hydroecology, it was thought poss ible to use SIMAO in a wider context, like biotechnological processes. Starting from specific problems posed by a batch fermentation, the D- xylose conversion into ethanol by the yeast Pichia stipitis, this pape r describes how was built and used a SIMAO model aimed at predicting t he fermentation issue from initial conditions, i.e. set-points values and substrate concentration.