title: AHL signaling molecules with a large acyl chain enhance biofilm formation on sulfur and metal sulfides by the bioleaching bacterium Acidithiobacillus ferrooxidans.
abstract: Biofilm formation plays a pivotal role in bioleaching activities of bacteria in both industrial and natural environments. Here, by visualizing attached bacterial cells on energetic substrates with different microscopy techniques, we obtained the first direct evidence that it is possible to positively modulate biofilm formation of the extremophilic bacterium Acidithiobacillus ferrooxidans on sulfur and pyrite surfaces by using Quorum Sensing molecules of the N-acylhomoserine lactone type (AHLs). Our results revealed that AHL-signaling molecules with a long acyl chain (12 or 14 carbons) increased the adhesion of A. ferrooxidans cells to these substrates. In addition, Card-Fish experiments demonstrated that C14-AHL improved the adhesion of indigenous A. ferrooxidans cells from a mixed bioleaching community to pyrite. Finally, we demonstrated that this improvement of cell adhesion is correlated with an increased production of extracellular polymeric substances. Our results open up a promising means to develop new strategies for the improvement of bioleaching efficiency and metal recovery, which could also be used to control environmental damage caused by acid mine/rock drainage.
authors: Laboratory of Bacterial Communication, Department of Biology, Faculty of Sciences, University of Chile, Santiago, Chile.
authors: Alex
authors: A
authors: González
authors: Sören
authors: S
authors: Bellenberg
authors: Sigde
authors: S
authors: Mamani
authors: Lina
authors: L
authors: Ruiz
authors: Alex
authors: A
authors: Echeverría
authors: Laurent
authors: L
authors: Soulère
authors: Alain
authors: A
authors: Doutheau
authors: Cecilia
authors: C
authors: Demergasso
authors: Wolfgang
authors: W
authors: Sand
authors: Yves
authors: Y
authors: Queneau
authors: Mario
authors: M
authors: Vera
authors: Nicolas
authors: N
authors: Guiliani
mesh_terms: D042763:Acidithiobacillus / Q000187:drug effects / Q000502:physiology*; D054742:Acyl-Butyrolactones / Q000378:metabolism*; D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D007501:Iron / Q000378:metabolism*; D008670:Metals / Q000378:metabolism*; D011108:Polymers / Q000378:metabolism; D053038:Quorum Sensing / Q000187:drug effects*; D015398:Signal Transduction / Q000187:drug effects*; D013440:Sulfides / Q000378:metabolism*; D013455:Sulfur / Q000378:metabolism
chemical_list: D054742:Acyl-Butyrolactones; D008670:Metals; D011108:Polymers; D013440:Sulfides; C011342:pyrite; D013455:Sulfur; D007501:Iron