How Biofilms Work

By: Marianne Spoon

Benefits of Biofilms

As we just learned, microorganisms can cause imbalance in an environment if the conditions are right. Ironically, that's why microbes can be beneficial, too. For instance, it turns out that the same nutrient-hungry bacteria that break down carbon in treated water can also restore balance to an area by eating excess carbon when the situation arises.

When oil accidentally winds up in nature (as seen in oil spills), microbes slowly break down oil particles. Since oil is primarily made of carbon, there are a variety of bacteria that break down small oil molecules for food. With this line of thinking, it's feasible to say that biofilms can be potential tools to clean up environmental messes. Using biofilms in this way is an example of bioremediation, or returning an environment from an altered state back to its natural one with the help of microorganisms. Though collecting oil and running it through a biofilm filter of some sort isn't a common method to clean up oil spills today, it may be an interesting option to explore in the future.


Biofilms even have their place in the mining industry. Quite often, valuable ore is separated from normal rock in mining settings. But in the presence of water and oxygen, certain types of leftover crushed rock can create a sulfuric acid solution if left alone. Once the reaction takes place, this acid and other runoff are hard to clean up and can pollute nearby water sources. But if you take out a part of the equation, the rock material won't become acidic and can be disposed of differently. It turns out that placing biofilm-forming bacteria that need oxygen on these rocks will strip the element from its surface and disable this acid runoff from forming [source: Sturman].

In addition to bioremediation, biofilms can be used in biofilm trickling filters to treat waste water [source: Sturman]. In this process, biofilms are grown on rocks or pieces of plastic to clean wastes out of the water slowly trickling through. On a small scale, this process is efficient enough, but most municipal water treatment centers still rely on larger quantities of bacteria to treat wastewater.

Biofilms also benefit other organisms in nature. Underground, microorganisms will form a biofilm around the rhizosphere, or the area between roots and soil, in plants. Chemical interactions in this symbiotic relationship grant both parties access to nutrients that would otherwise not be available. Biofilm formation on plant roots is one of many examples of why biofilms are ecologically important.

Think you know biofilms yet? Find out ways to battle unwanted colonies next.