As we've learned, these communal microbes can adapt to live on many surfaces, including our teeth and in our bodies, but the vast majority of biofilms are found in nature. For instance, you may feel the presence of biofilms on rocks in a shallow body of water, creating a slippery surface to traverse. Unlike biofilms studied in the lab, these aggregations occur naturally and are one part of a larger ecosystem.
Today, our impact on the environment often results in imbalances in ecosystems. For example, waste runoff can cause an area to have higher levels of certain nutrients than usual. To some microorganisms, this means more food to eat, and their populations may grow out of control as a result. But in order to break down nutrients, some microbes require oxygen, and they will use more than usual to break down a surplus of nutrients. This removal of oxygen from an ecosystem can cause problems for other organisms that share the same habitat, sometimes resulting in dead zones. If given the nutrients to grow out of control, both free-floating microorganisms and sedentary biofilms can flourish and use all of the oxygen in an area, making an environment hard or impossible to live in for other microbes and animals.
In industrial environments, biofilms are a force to be reckoned with. Since most production facilities use water to cool equipment or depend on pipes to transport resources, there's a substantial risk of developing biofilms on these equipment and piping systems. According to one estimate, biofilms cause well over a billion dollars' worth of damage every year in industrial settings, affecting human health and companies' abilities to manufacture their products efficiently [source: Montana State University CBE; Sturman]. Papermaking facilities are especially at risk for biofilm problems, because manufacturing paper requires a lot of water and provides a warm and nutritious environment for microorganisms to grow [source: Sturman].
Biofilms can also negatively affect the quality of drinking water. After waste water is treated, it flows through clean pipes that transport it to our faucets. But in some cases, biofilms can be a nuisance in this process. Scientists at water treatment facilities found that biofilms still form in the pipes that carry clean water, which re-contaminates the water. After studying the issue, they learned that clean drinking water that has been treated contains organic carbon -- a tasty meal for bacteria. Fortunately, removing organic carbon from processed water limits these bacterial biofilms from forming in clean water pipes, granting the water a safe trip to your faucet [source: Sturman].
Biofilms can cause problems, but they can also be beneficial. Continue to the next page to read about how biofilm technology can clean up environmental messes.