ABSTRACT
Laboratoire Universitaire de Biodiversité et d’Ecologie Microbienne, Université de Bretagne Occidentale, 29000 Quimper, France. Emails: desriac@univ-brest.fr; cjegou@univ-brest.fr; Benjamin.Brillet@univ-brest.fr; lecheval@univ-brest.fr
* Corresponding author: fl eury@univ-brest.fr
The ocean represents more than two-thirds of the earth’s surface. The marine environment presents one of the greatest biodiversities on earth at both the eukaryotic and prokaryotic levels. Indeed, marine organisms live in a real microbial “soap”. Bacterial and fungal concentrations have been estimated to be around respectively 104 CFU.mL-1 and 103 CFU.mL-1 (Zweifel and Hagstrom 1995) while viral particle concentration is evaluated at 3.106 VLP. mL-1 (Suttle 2005). Beyond this dense biodiversity, the liquid nature itself of the aquatic environment introduces proximity and continuity. To survive and thrive in such a medium, aquatic animals have had no alternative than to associate with benefi cial micro-organisms to occupy the ecological niche and to prevent pathogenic implantation and/or to produce potent chemical weapons to fi ght against the pathogenic microbes. In the light of such selection pressure, marine animals may constitute a huge reservoir of effi cient antimicrobial compounds and of symbiotic association with microorganisms. Paradoxically, antimicrobial compounds from marine sources, are anecdotic compared to the terrestrial sources, probably due to technical diffi culties involved in sample collection. Investigation of marine pharmacology literature for antimicrobial compounds from 1998 to 2010 resulted in the identifi cation of four main structural families-polyketides (27%), terpenoids (20%), peptides (16%) and alkaloids (15%) (Mayer and Hamann 2002, 2004, 2005, Mayer et al. 2007, 2009, 2011). To date, various antimicrobial compounds from the sea have been isolated, characterized and investigated in clinical trials (for review see references Donia and Hamann 2003, Blunt et al. 2004, Bhatnagar and Kim 2010, Montaser and Luesch 2011).
