A biofilm is a community of microorganisms that adhere to each other and/or to a surface. They do this by forming a matrix of extracellular polysaccharides or other polymeric substances. Biofilms can be as thin as plaque on your teeth and residue in a shower or they can be a mat up to several centimeters thick. Virtually all bacteria are capable of forming a biofilm. Because they can form on both living and non-living surfaces, biofilms are the most prevalent mode of microbial life in most settings. What’s more, cells in biofilms are physiologically distinct from cells found in liquid cultures.
Where are biofilms found?
Biofilms are found in a large number of natural and industrial settings. They can form on rocks and pebbles at the bottom of streams and on the surface of stagnant water. They are found in extreme environments such as hot springs, glaciers, and interfaces between gas and air such as coastal areas and deep sea vents. In these environments, biofilms grow in layers that form a thick and hard microbial mat. The mat not only protects them from the environmental extremes but organizes them into physiologically distinct groups that are capable of utilizing each others cellular by-products. Biofilms can also be found in showers, pipes, boat hulls, plants, teeth (plaque) and tissues (lungs).
Why are they important?
Biofilms are thought to be even more ubiquitous than planktonic bacteria. For that reason alone they are interesting, however, biofilms also play a major role in antibiotic resistance, gum disease, and bioremediation. Biofilms are also the major cause of bacterial infections arising from the implant of medical devices such as catheters and heart valves. Further a number of chronic infectious diseases are caused by biofilms, including cystic fibrosis.
Microorganisms that have organized into biofilms express a very different set of genes than those growing in planktonic phases. However, the bulk of gene expression research has focused more on bacteria growing as pure liquid cultures rather than with a wide range of organisms as found in biofilms. Given the large number of industrial applications for biofilm and the need for better methods to eradicate these persistant communities both on medical devices and in human infections, research on biofilm has grown substantially in the last several years.
Bringing down barriers to biofilm research
Typical nucleic acid extraction techniques are not successful at disrupting the extracellular matrices created by biofilm formation. Biofilms also tend to concentrate inhibitors (humic substances, metals, salts, pesticides) to both nucleic acid extraction and subsequent analysis. This contaminant carryover typically leads to extraction of small amounts of DNA or RNA that are of poor quality. MO BIO’s PowerBiofilm® DNA and RNA Isolation kits pair a brand-new bead beating and cell lysis technology with our patented Inhibitor Removal Technology® (IRT) for increased yields of inhibitor free DNA and RNA from all types of biofilms, including microbial mats.