The Effects of Glycerol on Biofilm Production

Abstract

Due to the widespread, antibiotic-resistant nature of biofilm-producing bacteria, there is high demand for research on biofilm formation.  This research serves as a contribution to the existing knowledge of how biofilms form.  Its results could shed light on how biofilm-producing bacteria utilize communication pathways in response to environmental and chemical stimuli.  To determine the effects of glycerol (a sugar alcohol linked to osmotic stress) on biofilm production, Pseudomonas fluorescens strain SBW25 was cultivated within a series of 5 culture tubes containing medias with increasing concentrations of glycerol from 0-10%.  After a week of incubation, a sample from each of the tubes was plated and colony morphology was qualitatively analyzed.  Each of the tubes was then stained with crystal violet and the absorbance of the biofilm could be quantitatively measured at 590nm with a dual-beam spectrophotometer.  The hypothesis is supported with the absorbance and plate data collected over the first and second trials of the experiment.  As glycerol concentration increased, the absorbance (and thus biofilm produced) increased proportionately, and the approximate number of wrinkly mutants on each successive plate increased.  The correlation of the data is significant enough to support the hypothesis, but more trials will need to be conducted in order to conclusively accept it.