The project ULIXES aims to unravel, categorize, catalogue, exploit and manage the microbial diversity available in the Mediterranean Sea for addressing bioremediation of polluted marine sites. The idea behind ULIXES is that the multitude of diverse environmental niches of the Mediterranean Sea contains a huge range of microorganisms and their components (e.g. catabolic enzymes) or products (e.g. biosurfactant) that can be exploited in pollutant- and site-tailored bioremediation approaches. ULIXES intends to provide the proof of concept that it is possible to establish and exploit for bioremediation site-specific collections of microbial strains, mixed microbial cultures, enzymes, biosurfactants and other microbial products. These biotechnological resources will be mined by using approaches based on isolation of culturable microorganisms as well as by extensively applying advanced novel ‘meta-omics’ technologies recently developed by the project partners and exclusively available for ULIXES. Three pollutant classes recognized worldwide as environmental priorities will be considered: petroleum hydrocarbons, chlorinated compounds and heavy metals. A large set of polluted environmental matrices from sites located all over the Mediterranean Sea will be explored, including seashore sands, lagoon sediments, deep sea sediments polluted by heavy oil hydrocarbons at oil tanker shipwreck sites, hypersaline waters and sediments from polluted salty coastal lakes and natural deep hypersaline anoxic submarine basins and mud volcanoes where hydrocarbon seepages occur. The mined collections of microbial biotechnological products will be exploited for development of novel improved bioremediation processes whose effectiveness will be proved by ex situ and in situ field bioremediation trials. A careful dissemination action will be pursued to assure capillary information of the ULIXES results and products to stakeholders and SMEs operating in the sector of marine bioremediation.