title: Dimethyl sulfoxide and ethanol elicit increased amyloid biogenesis and amyloid-integrated biofilm formation in Escherichia coli.
abstract: Escherichia coli directs the assembly of functional amyloid fibers termed "curli" that mediate adhesion and biofilm formation. We discovered that E. coli exhibits a tunable and selective increase in curli protein expression and fiber assembly in response to moderate concentrations of dimethyl sulfoxide (DMSO) and ethanol. Furthermore, the molecular alterations resulted in dramatic functional phenotypes associated with community behavior, including (i) cellular agglutination in broth, (ii) altered colony morphology, and (iii) increased biofilm formation. Solid-state nuclear magnetic resonance (NMR) spectra of intact pellicles formed in the presence of [(13)C(2)]DMSO confirmed that DMSO was not being transformed and utilized directly for metabolism. Collectively, the chemically induced phenotypes emphasize the plasticity of E. coli's response to environmental stimuli to enhance amyloid production and amyloid-integrated biofilm formation. The data also support our developing model of the extracellular matrix as an organized assembly of polymeric components, including amyloid fibers, in which composition relates to bacterial physiology and community function.
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California, USA.
authors.forename: Ji Youn
authors.initials: JY
authors.lastname: Lim
authors.forename: Janine M
authors.initials: JM
authors.lastname: May
authors.forename: Lynette
authors.initials: L
authors.lastname: Cegelski
mesh_terms: D000682:Amyloid / Q000096:biosynthesis*; D001422:Bacterial Adhesion / Q000187:drug effects; D001426:Bacterial Proteins / Q000096:biosynthesis*; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D004121:Dimethyl Sulfoxide / Q000378:metabolism*; D004926:Escherichia coli / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D000431:Ethanol / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy
chemical_list: D000682:Amyloid; D001426:Bacterial Proteins; C077481:Crl protein, Bacteria; D000431:Ethanol; D004121:Dimethyl Sulfoxide