(Montana State University - Bozeman, College of Engineering, 2007) Klayman, Benjamin Joseph; Chairperson, Graduate Committee: Anne Camper
This research represents a novel approach for describing biofilm accumulation at multiple scales of observation in both single and dual-species biofilms. Pseudomonas aeruginosa PAO1 and Escherichia coli O157:H7 were grown as single and dual-species biofilms in 1 mm glass capillary flow cells and monitored over time using confocal microscopy. Colonization and biofilm development patterns were associated with the fluid flow regime as evaluated using the finite volume analysis program CFX (ANSYS Europe, Ltd). The shear stress was shown to vary along the surface from a minimum near the edges to a maximum in the center of the flow path. Initial colonization by both species occurred at the outer edges of the flow path (low shear). P. aeruginosa was subsequently observed to migrate perpendicular to the flow direction towards the center of the flow path (high shear), but E. coli was never observed outside of the 200 micron outer edge. E. coli was unable to persist in the flow cell unless P. aeruginosa was present as a colonizing partner. Bio-volumes of each species were calculated using the Metamorph (Molecular Devices) image analysis program and are reported over time.
