Biofilm facts for kids

A biofilm is a group of tiny living things, like microorganisms (microbes), that stick together on a surface. They often create a slimy layer around themselves. Think of it like a tiny, sticky city built by microbes!

These tiny cells in a biofilm produce special sticky stuff. This includes things like sugars (called polysaccharides), proteins, fats (called lipids), and even their genetic material (DNA). Because they form a three-dimensional structure, biofilms are like a community where microbes live together. People sometimes call them "cities for microbes" because they are so organized.

In these microbial cities, the bacteria can share nutrients (food) with each other. They are also protected from things that could harm them. This includes drying out (desiccation), antibiotics (medicines that kill bacteria), and even the body's own defense system (immune system). A common example of a biofilm is the film of bacteria that lives on your teeth, which we call plaque. Biofilms can also form on non-living things, like stones in a river.

What Are Biofilms?

Biofilms are not just random groups of microbes. They are organized communities. The microbes in a biofilm work together, almost like a team. This teamwork helps them survive and grow in different places.

How Biofilms Form

Biofilms form in several steps. First, tiny microbes attach to a surface. Then, they start to multiply and produce the sticky slime. This slime helps them stick even better and protects them. Over time, more microbes join, and the biofilm grows thicker and stronger.

Stages of Biofilm Development

Scientists have identified five main stages of how a biofilm grows:

• Initial attachment: Microbes first lightly stick to a surface.
• Irreversible attachment: They stick more firmly and start to produce their sticky protective layer.
• Maturation I: The biofilm begins to grow and form a thicker structure.
• Maturation II: The biofilm becomes fully developed, with different areas and types of cells.
• Dispersion: Some microbes can break away from the biofilm. They then go off to start new biofilms in other places.

Where Do We Find Biofilms?

Biofilms are everywhere! They can be found in many different environments.

• In your body: Besides your teeth, biofilms can form in other parts of the body. Sometimes, they can cause infections, especially on medical devices like catheters.
• In nature: You can see biofilms in hot springs, rivers, and even in the soil. They play an important role in many natural processes. For example, the colorful mats you see in hot springs are often huge communities of bacterial biofilms.
• In homes and industries: Biofilms can grow in water pipes, on kitchen counters, and in many industrial settings.

Why Are Biofilms Important?

Biofilms are important for many reasons, both good and bad.

Good Biofilms

• Nature's helpers: In nature, biofilms help clean water and break down waste. They are a key part of many ecosystems.
• Helpful in industry: Some biofilms are used in wastewater treatment plants to clean dirty water.

Bad Biofilms

• Health problems: Biofilms can cause stubborn infections in humans. Because the microbes are protected by the slime, it can be hard for medicines like antibiotics to reach and kill them.
• Damage to structures: Biofilms can cause pipes to clog or lead to corrosion (rusting) of metal structures.

Images for kids

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  Staphylococcus aureus biofilm on an indwelling catheter. This shows how bacteria can stick to medical devices.

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  Mature biofilm structure  A fully grown biofilm has different types of cells. Some are active, and some are resting. It also has a sticky layer made of sugars, DNA, and proteins. Bacteria in biofilms can communicate using a system called quorum sensing. This helps them work together and produce things that can make them stronger.
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  Five stages of biofilm development  This image shows the different steps a biofilm goes through as it grows. Each picture is a photomicrograph (a photo taken through a microscope) of a P. aeruginosa biofilm developing.
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  This is a scanning electron micrograph of a mixed-culture biofilm. It shows how different types of bacteria and their sticky substances are arranged together.

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  These colorful mats of bacterial biofilm are found in the hot springs of Yellowstone National Park.

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  This image shows thick mats of thermophilic bacteria (bacteria that love heat) in the outflow of Mickey Hot Springs, Oregon.

See also

In Spanish: Biopelícula para niños