title: Pseudomonas aeruginosa biofilm disruption using microbial surfactants.
abstract: OBJECTIVE
  To establish the ability of the rhamnolipids biosurfactants from Pseudomonas aeruginosa, in the presence and absence of caprylic acid and ascorbic acid, to disrupt bacterial biofilms, compared with the anionic alkyl sulphate surfactant Sodium dodecyl sulphate (SDS).
  
  
  RESULTS
  Pseudomonas aeruginosa ATCC 15442 biofilms were disrupted by rhamnolipids at concentrations between 0·5 and 0·4 g l(-1) and with SDS at 0·8 g l(-1) . The combination of rhamnolipids 0·4 g l(-1) and caprylic acid at 0·1 g l(-1) showed a remarkable effect on biofilm disruption and cell killing. After 30 min of treatment most of the biofilm was disrupted and cell viability was significantly reduced. Neither caprylic acid nor ascorbic acid has any effect on biofilm disruption at 0·1 g l(-1) . SDS is an effective antimicrobial agent; however, in the presence of caprylic acid its effect was neutralized.
  
  
  CONCLUSIONS
  The results show that rhamnolipids at low concentration in the presence of caprylic acid are promising molecules for inhibition/disruption of biofilms formed by Ps. aeruginosa ATCC 15442.
  
  
  CONCLUSIONS
  The disruption of biofilms has major significance in many industrial and domestic cleaning applications and in medical situations.
authors.affiliation: School of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK.
authors.forename: M A
authors.initials: MA
authors.lastname: Díaz De Rienzo
authors.affiliation: Unilever Research and Development Laboratory, Port Sunlight, Wirral, UK.
authors.forename: P S
authors.initials: PS
authors.lastname: Stevenson
authors.affiliation: School of Biomedical Sciences, University of Ulster, Coleraine, UK.
authors.forename: R
authors.initials: R
authors.lastname: Marchant
authors.affiliation: School of Biomedical Sciences, University of Ulster, Coleraine, UK.
authors.forename: I M
authors.initials: IM
authors.lastname: Banat
mesh_terms: D018441:Biofilms / Q000187:drug effects*; D006017:Glycolipids / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000502:physiology; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D013501:Surface-Active Agents / Q000494:pharmacology*
chemical_list: D006017:Glycolipids; D013501:Surface-Active Agents; C418382:rhamnolipid; D012967:Sodium Dodecyl Sulfate
keywords: Pseudomonas aeruginosa; ascorbic acid; biofilms; biosurfactants; caprylic acid; rhamnolipids