Biofilms: Their Dangers and Applications 

August 25, 2025

Monique Nguyen

Fountain Valley High School

12th Grade

Introduction:

Just about everybody has heard of bacteria—exceptionally small, unicellular prokaryotes, which are organisms without a nucleus and other membrane-bound organelles. These diverse microorganisms inhabit virtually every space on Earth, including the human body, with variable functions depending on type. For example, some types of harmless bacteria can aid with gut digestion and strengthen the immune system, while harmful ones may give rise to infections, like Salmonella and strep throat. While some bacteria function independently, many types work together and live in communities to produce the significant effects previously seen, such as the microbiome residing in the human gut to regulate gut health. Consequently, it’s likely not a surprise for multiple groupings of diverse bacteria to commonly accumulate with other types of microorganisms, like fungi and protists, on a substrate or surface, which can form something called a biofilm.

Biofilms are produced when communities of microorganisms naturally form complex, web-like structures with layers of microbes sticking together on a surface and growing based on their surrounding conditions. Initially, independent microbes like bacteria will stick onto a surface, and other microorganisms attach to grow into a bulb-like structure until the formation is stable; cells within the biofilm will then detach to search for a new surface in a process called seedling dispersal. The formation of the biofilm is irreversible unless there is no further construction when free-floating microbes first attach, so they can be found in a wide variety of sectors, including environmental, biological, and industrial ecosystems. Many biofilms are typically found in small water sources (e.g., pond scum), such as surface water, groundwater, rocks, soil, air, and other terrestrial ecosystems. Some are found in humans, aggregating or coming together using its and its host’s extracellular DNA (eDNA)—which is DNA that is found outside a cell—for structural support. Additionally, eDNA is often wrapped into a shape called Z-DNA, which is resistant to enzymes and helps with antimicrobial protection. To stay together, biofilms self-produce their glue, which comes in the form of extracellular polymeric substances—extracellular molecules released by microbes—that are very gooey; they’re often described as slimy and sticky for a reason. Biofilms have highly strong adhesive properties, meaning they like to stick very deeply to other surfaces. But the question is why these biofilms form and what their significance is to society as a whole. Well, biofilms may pose several unseen and typically serious dangers, so research on these biofilms is increasing to understand their functions, properties, and potential applications to a numerous range of sectors.

Dangers:

The effects of natural biofilms can be linked to a wide variety of threats, one of the most serious being antibiotic shielding. As bacteria form communities, the biofilm shields them from what they would typically encounter: various medications, harsh environments, and immune cells. This means that these microorganisms are exceptionally protected, so they do not have to spend their resources on defense and cell division, and they are more resistant to antibiotics. This is a hazardous effect, especially as research from the National Library of Medicine estimates that about 80% of bacteria related to chronic illnesses can form biofilms. If biofilms contain harmful bacteria, infections may become much more persistent due to the difficulty in destroying them; they may even lead to dangerous health conditions. Furthermore, if they accumulate in medical devices like catheters or prosthetics, this could lead to complicated device-related infections. If the effects of biofilms may not seem relevant to one’s everyday life, there is a common example that affects everyone: dental plaque. Unless one’s teeth are brushed thoroughly, bacteria could aggregate into a biofilm on the tooth or teeth, leading to health issues like cavities and inflammation. Another atypical example of biofilms is in factories. As they are highly adhesive, they can form on production lines and work surfaces, which also have bacteria and other microbes. These industry-related biofilms may corrode equipment, pipes, and machines as well as contaminate biological products like food. As a result, they can lead to health issues such as airborne illness in industry as well.

Applications:

Still, researchers are working to study the functionality and potential of biofilms in a multitude of ways. One example is an effort to synthetically replicate them by 3D-printing diverse bacterial communities in order to study their natural counterparts, effectively designing strategies to combat their negative effects and eradicate them. Because they are low cost, low risk, and highly efficient, biofilms are quite useful in bioremediation as well, which is essentially using biological systems as a filtering device—adsorbing, degrading, and removing pervasive pollutants such as toxic heavy metals, pesticides, hydrocarbons, and trace micro- and nanoplastics in the environment. A specific example is research conducted on their functionality in wastewater treatment when attached to various natural and waste-based carriers, such as clay, stones, and bamboo and wood husk, textile waste, and corncob, respectively. Other applications of biofilms are still growing, such as their application in synthetic glue and technology like the Biofilm-Integrated Nanofiber Display (BIND) to create self-assembling materials. 

Conclusion:

As advancements in areas like microbiology, pathology, and biotechnology grow, research to mitigate the large-scale risks of biofilms and target their functionalities for societal growth is still ongoing. Understanding the elaborate properties of these three-dimensional microbial communities along with their interactions with their substrates and variable environments will allow the applications of natural biofilms and their synthetic counterparts to be positively integrated in the future all the more effectively.