title: Involvement of Shewanella oneidensis MR-1 LuxS in biofilm development and sulfur metabolism.
abstract: The role of LuxS in Shewanella oneidensis MR-1 has been examined by transcriptomic profiling, biochemical, and physiological experiments. The results indicate that a mutation in luxS alters biofilm development, not by altering quorum-sensing abilities but by disrupting the activated methyl cycle (AMC). The S. oneidensis wild type can produce a luminescence response in the AI-2 reporter strain Vibrio harveyi MM32. This luminescence response is abolished upon the deletion of luxS. The deletion of luxS also alters biofilm formations in static and flowthrough conditions. Genetic complementation restores the mutant biofilm defect, but the addition of synthetic AI-2 has no effect. These results suggest that AI-2 is not used as a quorum-sensing signal to regulate biofilm development in S. oneidensis. Growth on various sulfur sources was examined because of the involvement of LuxS in the AMC. A mutation in luxS produced a reduced ability to grow with methionine as the sole sulfur source. Methionine is a key metabolite used in the AMC to produce a methyl source in the cell and to recycle homocysteine. These data suggest that LuxS is important to metabolizing methionine and the AMC in S. oneidensis.
authors.affiliation: Department of Geosciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA. learman@seas.harvard.edu
authors.forename: Deric R
authors.initials: DR
authors.lastname: Learman
authors.forename: Haakrho
authors.initials: H
authors.lastname: Yi
authors.forename: Steven D
authors.initials: SD
authors.lastname: Brown
authors.forename: Stanton L
authors.initials: SL
authors.lastname: Martin
authors.forename: Gill G
authors.initials: GG
authors.lastname: Geesey
authors.forename: Ann M
authors.initials: AM
authors.lastname: Stevens
authors.forename: Michael F
authors.initials: MF
authors.lastname: Hochella
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D018441:Biofilms / Q000254:growth & development*; D013437:Carbon-Sulfur Lyases / Q000235:genetics / Q000502:physiology*; D017353:Gene Deletion; D020869:Gene Expression Profiling; D005816:Genetic Complementation Test; D006714:Homoserine / Q000031:analogs & derivatives / Q000378:metabolism; D007783:Lactones / Q000378:metabolism; D008715:Methionine / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D020592:Shewanella / Q000235:genetics / Q000502:physiology*; D013455:Sulfur / Q000378:metabolism*; D014733:Vibrio / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D007783:Lactones; C091088:N-octanoylhomoserine lactone; D006714:Homoserine; D013455:Sulfur; D008715:Methionine; D013437:Carbon-Sulfur Lyases; C117753:LuxS protein, Bacteria