Whole cell, strength of adhesion assays of three different isolates of the fouling diatom Amphora coffeaeformis were compared using a hydrophilic surface viz. acid washed glass (AWG), and a hydrophobic surface viz. a self assembled monolayer (SAM) of undecanethiol (UDT).
View Article and Find Full Text PDFDiatoms are a major component of the biofoul layer found on modern low-surface-energy, 'foul release' coatings. While diatoms adhere more strongly to hydrophobic, as opposed to hydrophilic, surfaces, surprisingly little is known of the chemical composition of their adhesives. Even less is known about the underlying processes that characterize the interaction between the adhesive and a given surface, including those of differing wettability.
View Article and Find Full Text PDFA species of marine diatom, Toxarium undulatum, has emerged as a problematic biofouler of contemporary environmentally benign marine coatings. Previous analyses by atomic force microscopy (AFM) showed the cell-substratum adhesive of this alga contained macromolecules with a modular protein backbone assembled into nanofibers in which the domains of the macromolecules folded and unfolded in a co-ordinated manner. In the present study, we investigated further the composition and properties of the adhesive.
View Article and Find Full Text PDFThe quartz crystal microbalance with dissipation monitoring (QCM-D) was used to monitor the deposition of adhesive extracellular polymeric substances (EPS) employed by the marine biofouling diatoms Craspedostauros australis Cox and Amphora coffeaeformis Cleve during initial adhesion and subsequent motility. Upon injection into the QCM chamber, initial negative frequency (f) shifts and positive dissipation (D) shifts were measured that correlated to cells impacting and adhering to the QCM sensor surface. Following this "initial adhesion" response, f continued to decrease while D increased logarithmically.
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