Quorum Quenching Strains Isolated from the Microbiota of Sea Anemones and Holothurians Attenuate Vibrio corallilyticus Virulence Factors and Reduce Mortality in Artemia salina Reina, José Carlos Pérez, Pedro Llamas Company, Inmaculada Quorum quenching N-acylthomoserine lactone Acylase Marine bacteria Sea anemones Holothurians The English text was corrected by Michael O'Shea. This research was funded by the Spanish Ministry of the Economy and Competitiveness (grant number PID2019-106704RB-100/AEI/10.13039/501100011033). Jose Carlos Reina is supported by an FPU fellowship from the Spanish Ministry of Education, Culture and Sport (fellowship number FPU15/01717). Interference with quorum-sensing (QS) intercellular communication systems by the enzymatic disruption of N-acylhomoserine lactones (AHLs) in Gram-negative bacteria has become a promising strategy to fight bacterial infections. In this study, seven strains previously isolated from marine invertebrates and selected for their ability to degrade C6 and C10-HSL, were identified as Acinetobacter junii, Ruegeria atlantica, Microbulbifer echini, Reinheimera aquimaris, and Pseudomonas sihuiensis. AHL-degrading activity against a wide range of synthetic AHLs were identified by using an agar well diffusion assay and Agrobacterium tumefaciens NTL4 and Chromobacterium violaceum CV026 and VIR07 as biosensors. High-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis indicated that this activity was not due to an AHL lactonase. All the strains degraded Vibrio coralliilyticus AHLs in coculture experiments, while some strains reduced or abolished the production of virulence factors. In vivo assays showed that strains M3-111 and M3-127 reduced this pathogen’s virulence and increased the survival rate of Artemia salina up to 3-fold, indicating its potential use for biotechnological purposes. To our knowledge, this is the first study to describe AHLdegrading activities in some of these marine species. These findings highlight that the microbiota associated with marine invertebrates constitute an important underexplored source of biological valuable compounds. 2022-04-21T06:52:31Z 2022-04-21T06:52:31Z 2022-03-16 journal article Reina, J.C.; Pérez, P.; Llamas, I. Quorum Quenching Strains Isolated from the Microbiota of Sea Anemones and Holothurians Attenuate Vibrio corallilyticus Virulence Factors and Reduce Mortality in Artemia salina. Microorganisms 2022, 10, 631. [https://doi.org/10.3390/microorganisms10030631] http://hdl.handle.net/10481/74417 10.3390/microorganisms10030631 eng http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España MDPI