Actinobacteria are a large group of Gram-positive bacteria, highly prolific in the production of bioactive secondary metabolites with a wide range of biological and pharmaceutical properties. Most of known actinobacterial species are of terrestrial origin, but it has been recently shown that they are also "true" habitants of the oceans and are a proven source of novel relevant secondary metabolites. The present proposal intends to explore the untapped and vast deepsea area of Portugal in terms of native actinobacteria and their potential to produce novel secondary metabolites with antimicrobial, anti-inflammatory, anticancer and antiobesity activities and biosurfactants. To accomplish the objectives of the project, both culture-dependent and independent approaches will be employed. Actinobacteria will be isolated from various deep-sea samples from continental Portugal and Azores and Madeira islands and screened for their capacity to produce target bioactive secondary metabolites. Metagenomic libraries will be constructed from selected deep-sea samples and will be screened for genes encoding biologically active compounds. The most promising bioactive metabolites will be subjected to detailed chemical analyses for identification of the chemical structure(s) responsible for the bioactivity. Some actinobacterial isolates will be also selected for genome sequencing. It is the aim of the project to discover novel drugs that may help in the future to fight diseases such as cancer, multiresistant bacterial infections and obesity that affect millions of people worldwide, and novel biosurfactants that can meet the needs of bioeconomy-based societies.