Title: Quorum signal molecules as biosurfactants affecting swarming in Rhizobium etli
Authors: Daniels, Ruth
Reynaert, Sven
Hoekstra, Hans
Verreth, Christel
Janssens, Joost
Braeken, Kristien
Fauvart, Maarten
Beullens, Serge
Heusdens, Christophe
Lambrichts, Ivo
De Vos, Dirk
Vanderleyden, Jozef
Vermant, Jan
Michiels, Jan # ×
Issue Date: Oct-2006
Publisher: National Academy of Sciences
Series Title: Proceedings of the National Academy of Sciences of the United States of America vol:103 issue:40 pages:14965-14970
Abstract: Swarming motility is suggested to be a social phenomenon that enables groups of bacteria to coordinately and rapidly move atop solid surfaces. This multicellular behavior, during which the apparently organized bacterial populations are embedded in an extracellular slime layer, has previously been linked with biofilm formation and virulence. Many population density-controlled activities involve the activation of complex signaling pathways using small diffusible molecules, also known as autoinducers. In Gram-negative bacteria, quorum sensing (QS) is achieved primarily by means of N-acylhomoserine lactones (AHLs). Here, we report on a dual function of AHL molecules in controlling swarming behavior of Rhizobium etli, the bacterial symbiotic partner of the common bean plant. The major swarming regulator of R. etli is the cinIR QS system, which is specifically activated in swarming cells by its cognate AHL and other long-chain AHLs. This signaling role of long-chain AHLs is required for high-level expression of the cin and rai QS systems. Besides this signaling function, the long-chain AHLs also have a direct role in surface movement of swarmer cells as these molecules possess significant surface activity and induce liquid flows, known as Marangoni flows, as a result of gradients in surface tension at biologically relevant concentrations. These results point to an as-yet-undisclosed direct role of long-chain AHL molecules as biosurfactants.
ISSN: 0027-8424
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Centre of Microbial and Plant Genetics
Soft Matter, Rheology and Technology Section
Centre for Surface Chemistry and Catalysis
Microbial and Molecular Systems - miscellaneous
Bioengineering Technology TC, Technology Campus De Nayer Sint-Katelijne-Waver
Technologiecluster Bioengineering Technologie
× corresponding author
# (joint) last author

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