Comparing metabolic networks at pathway level

Metabolic pathway comparison between different species is important to discover the differences in a metabolic function developed during the evolutionary process. This kind of analysis may allow the detection of important information useful also in drug engineering and medical science. In this thesis we propose a method for metabolic pathways comparison based on their representation as sets and multisets of chemical reactions. The information is taken from the KEGG database because it has a standardised representation of each pathway in the different organisms. The pathway comparison technique is then used in the context of metabolic networks comparison in order to solve the problems due to the size of the compared networks. The proposed methods have been implemented in Java as part of a tool for metabolic networks comparison.