Interceptación de señales de comunicación bacteriana en bacterias aisladas del medio marino

摘要: The term Quorum sensing (QS) was coined to describe the ability of bacteria perceive and respond population density for collective regulation gene expression, allowing social coordinated behaviors. Bacteria communicate using small chemicals called autoinducers (AIs) or pheromones. A high number use QS systems which can control important functions, including pathogenicity processes, such as: antibiotic biosynthesis, virulence, plasmid conjugal transfer, swarming, endospores formation biofilm differentiation. These signals allow pathogens coordinate attack beat host defenses. best studied signaling system involves N-acylhomoserine lactones (AHLs), that are constituted by an acyl chain N-bound a homoserine lactone ring (HSL), confers variability molecule because it change in length substitutions. AHLs have been described as being exclusively produced relatively α-, βand γ-Proteobacteria, but recently production these has also reported colonial cyanobacterium Gloeothece several members phylum Bacteroidetes, reinforces role AHL-mediated natural populations study putative biotechnological applications processes. Since bacterial communication plays key many physiological functions bacteria, virulence on plants animals, there is great interest design implementation inactivate QS, process quenching (QQ), could function new antiphatogenic strategy. One major interests QQ approach blocks expression factors does not exert selective pressure affect pathogen survival, therefore avoiding appearance resistances. Although inactivation all equally interesting, known date. Therefore become interesting alternative resistance human health aquaculture field. With aim frequency activity among marine obtain strains with potential, from sediment fish culture tank; filtered water reservoir tank biofilm; 133 Revista Real Academia Galega de Ciencias. Vol. XXIX algae Fucus vesiculosus, estuary open ocean at 0 10 meters depth, were isolated different media temperatures. isolates enzymatic degradation against AHL shows may be common cultivable environments, near shore samples waters. Out 630 isolates, 109 presented tested AHLs, represents 17.3% analysed almost order magnitude higher than obtained soil (2%). It possible identify isolate capable antagonize activity, although this still needs characterized. Culture isolating temperatures did percentage while sample origin strongly influenced specially vesiculosus (39.4% active strains) waters depth (27.7 27.7% respectively). Twenty interfereing whole range sizes identified their 15 them dense communities 5 water, most belonging strictly genera. wide spectrum showed taxonomic variability, genera classified phyla α-; γ-Proteobacteria (6, species close Phaeobacter); Actinobacteria (1); Firmicutes (2) Bacteroidetes (1). belonged (1) (2), Maribacter. observed discrepancy between enzyme sequences available metagenomes. This related low homology shown enzymes existence yet unknown activities. activities present will surely extend our knowledge degrading inhibitory well drive development treatment prevention infections controlled especially field aquaculture, human, animal plant health. 134