title: Confocal Raman microspectroscopy as a tool for studying the chemical heterogeneities of biofilms in situ.
abstract: OBJECTIVE
  To investigate the use of confocal Raman microspectroscopy (CRM) for the analysis of the structure, composition and development of fully hydrated biofilms.
  
  
  RESULTS
  Pseudomonas aeruginosa PAO1 biofilms were cultured in a flow cell in minimal nutrient medium (artificial sea water) and their development was followed for up to 3 weeks. The spectroscopic signature of the biofilm cells and extracellular polymeric substances (EPS) were differentiated and their distribution in biofilm colonies and within water channels was mapped in-plane and -depth. The colonies were initially amorphous, mainly composed of cells with no detectable amount of EPS. They developed rapidly to give round colonies composed of a cellular core enclosed in a sheath of EPS. The EPS continued to increase and spread throughout the biofilm to become the dominating feature of aged colonies. Colonies with a liquid core morphology - characteristic of the seeding dispersal process - were also observed.
  
  
  CONCLUSIONS
  This study demonstrated that CRM can be used to monitor the distribution of biofilm components in fully hydrated undisturbed biofilms over time.
  
  
  CONCLUSIONS
  Confocal Raman microspectroscopy facilitates the analysis of hydrated, live bacterial biofilms as a function of space and time, thus making it a suitable technique for investigating the effects of various additives and environmental factors on biofilm growth.
authors.affiliation: Department of Chemistry, St Francis Xavier University, Antigonish, NS, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Sandt
authors.forename: T
authors.initials: T
authors.lastname: Smith-Palmer
authors.forename: J
authors.initials: J
authors.lastname: Pink
authors.forename: L
authors.initials: L
authors.lastname: Brennan
authors.forename: D
authors.initials: D
authors.lastname: Pink
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D001704:Biopolymers / Q000032:analysis; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D018613:Microscopy, Confocal; D011550:Pseudomonas aeruginosa / Q000737:chemistry / Q000502:physiology*; D013059:Spectrum Analysis, Raman / Q000379:methods
chemical_list: D001704:Biopolymers