Biofilms are a collective of one or more types of microorganisms that can grow on many different surfaces. Microorganisms that form biofilms include bacteria, fungi and protists.
1. One common example of a biofilm dental plaque, a slimy buildup of bacteria that forms on the surfaces of teeth. Pond scum is another example. Biofilms have been found growing on minerals and metals. They have been found underwater, underground and above the ground. They can grow on plant tissues and animal tissues, and on implanted medical devices such as catheters and pacemakers.
2. Biofilms thrive upon moist or wet surfaces.
3. Biofilms have established themselves in such environments for a very long time. Fossil evidence of biofilms dates to about 3.25 billion years ago, according to a 2004 article(opens in new tab) published in the journal Nature Reviews Microbiology.
4. For example, biofilms have been found in the 3.2 billion-year-old deep-sea hydrothermal rocks of the Pilbara Craton in Australia. Similar biofilms are found in hydrothermal environments such as hot springs and deep-sea vents.
1. Biofilm formation begins when free-floating microorganisms such as bacteria come in contact with an appropriate surface and begin to put down roots, so to speak. This first step of attachment occurs when the microorganisms produce a gooey substance known as an extracellular polymeric substance (EPS), according to the Center for Biofilm Engineering at Montana State University.
2. An EPS is a network of sugars, proteins and nucleic acids (such as DNA). It enables the microorganisms in a biofilm to stick together.
3. Attachment is followed by a period of growth. Further layers of microorganisms and EPS build upon the first layers. Ultimately, they create a bulbous and complex 3D structure, according to the Center for Biofilm Engineering.