The all-species living tree project

Résumé

The present thesis manuscript covers the following contents. (I) The creation of a type straindirected taxonomic tool based on a collection of reliable sets of prokaryotic rRNA sequences, universal alignments and trustworthy tree topologies, that are regularly updated and can be downloaded by the scientific community. (II) The challenge of achieving for the first time the complete catalogue of SSU sequences with all the hitherto classified species, consisting on the sequencing of more than 500 species that still remain missing. (III) Investigate, with the use of the database, fundamental aspects about taxonomy of prokaryotes such as: phylogenetic thresholds in new taxa circumscriptions, coherence of current taxonomy by means of phylogenetic schemas and relevance of the 16S rRNA gene in taxonomic studies.