title: Biofilm thickness variability investigated with a laser triangulation sensor.
abstract: Measurement of the surface roughness and thickness of biological films is laborious and usually destructive, thus hampering research in this area. We developed a laser triangulation sensor (LTS) set-up for the fast and nondestructive measurement of these biofilm parameters during growth. Using LTS measurements, the morphological development of a dichloromethane-(DCM) degrading biofilm cultured on a wetted-wall column was studied. The measurements show that the biofilm develops faster at the entrance of the reactor. The biofilm consisted of a base film in which microbial colonies were embedded. The biofilm-surface area gradually increased by 23% compared to the bare surface due to the formation of a large number of these colonies. The number and shape of these colonies were followed in time. Using LTS measurements, biofilms distinctly different in surface roughness could be distinguished in a laboratory trickling filter removing DCM from a waste gas. The consequences of the observed surface characteristics for the reaction-diffusion process in the biofilm and for the falling film hydrodynamics are discussed.
authors.affiliation: Eindhoven University of Technology, P.O. Box 513, STW 0.35; 5600 MB, The Netherlands. tgtcwo@chem.tue.nl
authors.forename: W J
authors.initials: WJ
authors.lastname: Okkerse
authors.forename: S P
authors.initials: SP
authors.lastname: Ottengraf
authors.forename: B
authors.initials: B
authors.lastname: Osinga-Kuipers
mesh_terms: D018441:Biofilms; D001709:Biotechnology / Q000295:instrumentation* / Q000379:methods*; D018929:Cell Culture Techniques / Q000295:instrumentation / Q000379:methods*; D002478:Cells, Cultured; D007834:Lasers; D015233:Models, Statistical; D015203:Reproducibility of Results; D013997:Time Factors