title: Construction and phenotypic characterization of M68, an RruI quorum sensing knockout mutant of the photosynthetic alphaproteobacterium Rhodospirillum rubrum.
abstract: Many bacterial species communicate using a complex system known as quorum sensing (QS) in which gene expression is controlled in response to cell density. In this study an N-acylhomoserine lactone (AHL) synthase (Rru_A3396) knockout mutant (M68) of Rhodospirillum rubrum S1H (WT) was constructed and characterized phenotypically under light anaerobic conditions. Results showed that R. rubrum WT produces unsubstituted, 3-OH and 3-oxo-substituted AHLs with acyl chains ranging from 4 to 14 carbons, with 3-OH-C8 being the most abundant. Growth, pigment content and swimming motility were found to be under the control of this LuxI-type QS system. In addition, cultivation in a low shear environment put forward the aggregative phenotype of M68 and linked biofilm formation to QS in R. rubrum S1H. Interestingly, QS-mutant M68 continued to produce decreased levels of 3-OH-C8-HSL, probably due to the presence of an extra HdtS-type AHL synthase.
authors.affiliation: Research Unit for Microbiology, Belgian Nuclear Research Centre (SCK•CEN), Boeretang 200, 2400 Mol, Belgium; Research Institute for Biosciences, Proteomics and Microbiology Laboratory, University of Mons, Avenue du champ de Mars 6, Mons, Belgium. Electronic address: sccatach@sckcen.be.
authors.forename: Sandra
authors.initials: S
authors.lastname: Condori
authors.affiliation: Center for Biomolecular Science, School of Molecular Medical Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom. Electronic address: Steve.Atkinson@nottingham.ac.uk.
authors.forename: Steve
authors.initials: S
authors.lastname: Atkinson
authors.affiliation: Research Unit for Microbiology, Belgian Nuclear Research Centre (SCK•CEN), Boeretang 200, 2400 Mol, Belgium. Electronic address: nleys@sckcen.be.
authors.forename: Natalie
authors.initials: N
authors.lastname: Leys
authors.affiliation: Research Institute for Biosciences, Proteomics and Microbiology Laboratory, University of Mons, Avenue du champ de Mars 6, Mons, Belgium. Electronic address: ruddy.wattiez@umons.ac.be.
authors.forename: Ruddy
authors.initials: R
authors.lastname: Wattiez
authors.affiliation: Research Unit for Microbiology, Belgian Nuclear Research Centre (SCK•CEN), Boeretang 200, 2400 Mol, Belgium. Electronic address: fmastrol@sckcen.be.
authors.forename: Felice
authors.initials: F
authors.lastname: Mastroleo
mesh_terms: D054742:Acyl-Butyrolactones / Q000737:chemistry / Q000378:metabolism; D000693:Anaerobiosis; D055786:Gene Knockout Techniques; D008025:Ligases / Q000235:genetics / Q000378:metabolism*; D008124:Locomotion; D010860:Pigments, Biological / Q000378:metabolism; D053038:Quorum Sensing; D012247:Rhodospirillum rubrum / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D054742:Acyl-Butyrolactones; D010860:Pigments, Biological; D008025:Ligases; C449816:N-acylhomoserine lactone synthase
keywords: Biofilm; HdtS; Low shear environment; MELiSSA; Pigments; Quorum sensing