Funded by: PPG, Inc., January 15, 2002 -
Contact information: Phone: 814-863-7908,
Investigators: Bruce Logan, Penn State
University; Cory Steffak, PPG Inc.
Bacterial attachment can occur on any surface.
Bacteria, as well as other organic debris, are abundant in both
aqueous and atmospheric systems. Typical bacteria concentrations
even in very clean streams vary from 104 to 106 cells per mL and can
average 106 to 107 per mL in some lake and marine waters. Bacteria
are also abundant in the air. Total culturable cell counts in houses
in temperate zones average 900 per cubic meter, with fungal spores
reaching somewhat higher concentrations of 103 m-3. These are likely
underestimates (by two to three orders-of-magnitude) due to a lack
of sufficient techniques to fully ascertain bacterial counts.
Biofouling of surfaces has large industrial and
economic consequences. The formation of a biofilm can lead to a
complete change in the interfacial properties of the surface (i.e.
the exposed surface) and result in the loss of system performance.
Biofouling is a problem in diverse areas such as medical implants,
industrial heat exchangers, and marine surfaces. Bacterial adhesion
to different surfaces has been examined by the Logan group using
several different techniques developed in our laboratory, including;
fluorescent microscopy, large column tests, and mini-column tests
with bacteria tagged with radioisotopes. We have looked at bacteria,
phytoplankton and microsphere adhesion to a variety of surfaces
including many different types of fibers (glass, nylon, celluose,
polycarbonate), mesh, screens, glass, and soils. We have merged
these approaches with hydrodynamic models in order to quantify
initial adhesion event.
A collaborative effort is being undertaken
between Penn State researchers, led by Dr. Bruce Logan, and PPG to
investigate bacterial adhesion to various uncoated and coated
surfaces. This work is being performed at Penn State in conjunction
with an existing multi-investigator project funded for five years by
the National Science Foundation. It is expected that this research
will provide a greater understanding of the factors that promote
adhesion so that they may be controlled.