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Discovery of Complex Mixtures of Novel Long‐Chain Quorum Sensing Signals in Free‐Living and Host‐Associated Marine Alphaproteobacteria
Author(s) -
WagnerDöbler Irene,
Thiel Verena,
Eberl Leo,
Allgaier Martin,
Bodor Agnes,
Meyer Sandra,
Ebner Sabrina,
Hennig Andreas,
Pukall Rüdiger,
Schulz Stefan
Publication year - 2005
Publication title -
chembiochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 126
eISSN - 1439-7633
pISSN - 1439-4227
DOI - 10.1002/cbic.200500189
Subject(s) - roseobacter , alphaproteobacteria , quorum sensing , gammaproteobacteria , biology , homoserine , microbiology and biotechnology , bacteria , marine bacteriophage , biofilm , biochemistry , gene , genetics , phylogenetics , clade , 16s ribosomal rna
More than 100 bacterial isolates from various marine habitats were screened for AHL production by using gfp reporter constructs based on the lasR system of Pseudomonas aeruginosa and the luxR system of Vibrio fischeri . Of the 67 Alphaproteobacteria tested, most of which belonged into the so‐called Roseobacter clade, 39 induced fluorescence in either one or both sensor strains up to 103‐fold compared to controls. Acylated homoserine lactones were identified by GC‐MS analysis and shown to have chain lengths of C 8 , C 10 , C 13 –C 16 , and C 18 . One or two double bonds were often present, while a keto or hydroxyl group occurred only rarely in the side chain. Most strains produced several different AHLs. C 18 ‐en‐HSL and C 18 ‐dien‐HSL were produced by Dinoroseobacter shibae , an aerobic anoxygenic phototrophic bacterium isolated from dinoflagellates, and are among the longest AHLs found to date. Z7‐C 14 ‐en‐HSL, which has previously been detected in Rhodobacter sphaeroides, was produced by Roseovarius tolerans and Jannaschia helgolandensis . This signal molecule was synthesised and shown to induce a similar response to the culture supernatant in the respective sensor strain. The widespread occurrence of quorum‐sensing compounds in marine Alphaproteobacteria, both free‐living strains and those associated to eukaryotic algae, points to a great importance of this signalling mechanism for the adaptation of the organisms to their widely different ecological niches.