Gram-negative bacteria often use N-acyl homoserine lactones (AHLs) as quorum-sensing (QS) signal molecules. The present study aimed to identify and characterize the production of AHLs by Paracoccus sp. Ss63, which was isolated from the Mediterranean sponge Sarcotragus sp. High performance liquid chromatography - high resolution tandem mass spectrometry (LC-HRMS/MS) provided evidence for the production, by Paracoccus sp. Ss63, of twelve saturated long-chain AHLs (3-OH-C10-HSL, 3-OH-C12-HSL, C10-HSL, 3-OH-C14-HSL, C12-HSL, 3-O-C16-HSL, 3-OH-C16-HSL, C14-HSL, 3-OH-C18-HSL, C16-HSL, 3-O-C18-HSL, and C18-HSL), along with four putative unsaturated long-chain AHLs (C10: 1-HSL, 3-OH-C18: 1-HSL, C16: 1-HSL, and C18: 1-HSL). The distribution of Paracoccus sp. Ss63 in different sponge species, as well as in seawater and marine sediment samples, suggests a mixed lifestyle for this bacterium, i.e.; free-living and host-associated. The high pH of seawater is likely to inactivate the AHL signal molecules, and limit the possibility of AHLs to accumulate to the concentration required for QS-based gene regulation. We hypothesize that Paracoccus sp. Ss63 utilizes quorum sensing to sense and respond to the different environments it experiences, with an active QS only when found inside enclosed niches (host-associated and at lower pH).
Bibliographical noteFunding Information:
This study was supported by the Bilateral Italy?Israel R&D grant, MOST grant #10705?3 to L. S. The work was partially supported by the European Union's Seventh Framework Programme (FP7) 2007-2013 under Grant Agreement No. 311848 (Bluegenics). K. S. had a postdoctoral fellowship from the Israeli Council for Higher Education (VATAT) and University of Haifa. K. S.' postdoctoral fellowship was also supported by the "Universita degli Studi di Napoli Federico II" bilateral agreement Haifa?Naples 2015-2018. Samples were collected in compliance with the 40246/2014 permit from the Israel Nature and National Parks Protection Authority. K. S. is also thankful to Ms. Maya Britstein, Mr. Ilia Burgsdorf, and Dr. Markus Haber for assistance with sponge collection. Amplicon sequencing data from sponge and environmental microbiomes was derived from the Earth Microbiome Project (www.earthmicrobiome.org), all amplicon and metadata of project EMP 1 is public.
© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
- marine sponges
- quorum sensing
ASJC Scopus subject areas
- Chemistry (all)