And what is this slide about?  We want to leave you with the realization that not all biofilms are bad, or even ugly.  This is a picture of thermal pools at Mammoth Hot Springs in Yellowstone National Park in the Unites States.  The thermal pools are natural environments for biofilm growth in the form of algae.  Different water temperatures support different forms of algae of different colors, which lend these pools a remarkable beauty.  Of course, most of the study of biofilms is aimed at understanding and treating harmful biofilms that affect the efficiency or safety of industrial processes and human health.  However, there are natural, harmless biofilms that play a role in natural processes, as this picture illustrates. And, too, even biofilms that may be harmful in some situations are quite beneficial in others.  For example, the same biofilms that can thrive in an oil pipeline (by ingesting the oil), causing it to be able to transfer much less oil than it was designed for, can be used to remediate oil spills in the environment, where the ability of the biofilm to “eat” oil is exactly what is needed for helping clean up a spill.