Biofilm is a complex structure of multicellular colonies of microorganisms that are held together by means of an extracellular matrix. This self-produced matrix mainly consists of environmental DNA (eDNA), proteins, and polysaccharides, allowing biofilms to adhere to many different surfaces.
Along with being able to stick to almost anywhere and everywhere, biofilms are characterized by increased resistance to antibiotics and disinfectants. Therefore, being aware of what biofilms are and how they work is absolutely crucial for getting rid of them or preventing their formation in the first place.
While biofilms can lead to contamination in various industries and cause numerous infections, beneficial biofilms offer several advantages, especially for our environment. To make things easier to understand, here are 10 advantages and disadvantages of biofilms.
Advantages of Biofilms
Although biofilms are mainly known for their disadvantages, there are actually some “good” biofilms that offer several benefits.
The advantages of biofilms include the protection of the bacteria, the ability to purify water and clean up contaminated soil and groundwater, increasing soil fertility, and making mining for metals more eco-friendly.
Below are the pros of biofilms:
Biofilms Provide Protection for the Bacteria
Typically, biofilms are formed when microorganisms attach to surfaces (mostly in a moist environment) and start to reproduce. As these microorganisms secrete a slimy substance, biofilms are created. While some biofilms are formed by a single type of microorganism, others include a mixture of many bacteria species.
While biofilms can be pretty dangerous, they can also be beneficial, especially from microorganisms’ perspective. This is because biofilms act as survival sites for the bacteria by providing protection against antibiotics and disinfectants. Besides, biofilms also enhance the ability of the bacteria to survive and evolve.
Besides, according to the Antimicrobial Resistance & Infection Control Journal, biofilms protect microorganisms by altering pH, osmolarity, nutrient economy, and mechanical forces. In addition to that, these complex structures prevent the host’s immune cells and antibiotics from accessing the bacteria. Last but not least, reduced metabolic and growth rates make biofilms even more resistant.
Biofilms Can Be Used to Purify Water
While using biofilms to purify water may sound ridiculous, biofilms can actually improve the overall quality of water. Although treating wastewater and sewage with chemicals is an option, using microorganisms in the form of a biofilm is a more environmentally-friendly alternative.
If we take a look at the history of filtration systems and the water filtration techniques developed in the 19th century, we can conclude that adding chlorine might make water “cleaner” but still cause numerous health problems, especially repository diseases. Therefore, using biofilms to purify water could be a much better option.
In the past, engineers were often using natural biofilms without having any knowledge of biofilms. They would use sand as a filter medium for the microbes to attach to. Then these microorganisms would feed on the organic compounds found in water and wastewater. In other words, these beneficial biofilms would simply eat the materials contaminating the water.
Biofilms Can Clean Up Contaminated Soil and Groundwater
Beneficial applications of biofilms include the remediation of contaminated soil and groundwater. As mentioned above, biofilms feed on organic materials, meaning that they can clean up oil and gasoline spills in the soil and groundwater. In fact, certain types of naturally occurring bacteria in the soil can eat oil and gasoline. This process is often referred to as bioremediation.
According to these research articles on ScienceDirect, bioremediation is an emerging technique for removing or neutralizing environmental pollutants through metabolic processes initiated by biological organisms or biofilms. What makes this technology so advantageous is that it can be coupled with other physical and chemical treatment methods. Hence, this makes environmental pollution management more effective and sustainable.
Although bioremediation seems to be a legit idea, making it actually work requires further research and testing. Without sufficient knowledge of biofilms and environmental engineering systems, it would be hardly possible to select the right microorganisms for contaminated soil and groundwater treatment.
Biofilms Can Improve Soil Fertility
Another advantage of biofilms is improving soil fertility by means of different microorganisms. The technology involves the formation of a thin layer of microbes when applied to the soil.
According to this research paper on IOP Science, biofilms are excellent biological fertilizers (biofertilizers) or pesticides (biopesticides) that increase crop yields while conserving natural resources. This is mainly due to the fact that biofilms are resistant to various environmental stress factors, making them more effective than other fertilizers.
In addition, biofilm biofertilizers improve nutrient availability for plants by producing growth-promoting substances. Indole acetic acid (IAA) is a metabolite commonly produced by biofilm biofertilizers to promote plant growth.
Besides, as biofilm biofertilizers are naturally-occurring and there is no need to use chemical fertilizers, biofilms also promote food safety. Typically, biofilm biofertilizers are manufactured with organic ingredients and are considered chemical-free environmentally-friendly fertilizers.
Biofilms Can Make Mining for Metals More Environmentally-Friendly
Leaching is a chemical process during which soluble components are separated from insoluble materials by using a solvent. While this process occurs naturally, scientists have developed numerous applications of leaching for industrial purposes.
For instance, leaching is often used in the mining industry to extract metals from ores. While chemical leaching might be an effective technique, it results in toxic leftovers, affecting not only our environment but also human health.
To make mining more eco-friendly, scientists have developed ways to incorporate microorganisms in the leaching process. In microbial ore leaching, specific bacteria are selected and biofilms are used to consume the ore of interest and let the miners recover precious metals, like copper, gold, silver, lead, zinc, and nickel.
Along with decreasing environmental pollution, bioleaching can significantly reduce production costs. Besides, microorganisms can successfully extract metals even when their concentration in the ore is low.
Disadvantages of Biofilms
While biofilms have a few advantages, the cons outweigh the pros. Therefore, being aware of how dangerous biofilms can be is crucial for protecting not only ourselves but also the environment we live in.
The disadvantages of biofilms are contaminating medical equipment, increasing resistance to antibiotics and disinfectants, causing various infections, being responsible for food spoilage, and having a negative impact on water quality.
Below are the cons of biofilms:
Biofilms Contaminate Medical Equipment
Biofilms can grow on almost every type of surface you could possibly think of. And medical devices for internal and external use are no exception. This research article highlights that biofilm formation is considered one of the major virulence factors in infections associated with medical devices. Hence, researching and developing new approaches is absolutely crucial for preventing, diagnosing, or treating medical device-associated infections caused by biofilms.
Oftentimes, biofilms grow on medical implants and increase the risks of the patients getting infections. While some infections can be treated easily, others can lead to fatal results. As noted in this research paper, biofilm infections on implants or in-dwelling devices cause severe clinical complications and even lethal outcomes as they offer microorganisms better protection against antibiotics and macrophages.
Biofilms Increase the Resistance to Antibiotics and Detergents
As biofilm bacteria have altered physiology compared to planktonic bacteria, they are typically more resistant. Besides, these microorganisms are protected by extracellular polymeric substances, making them even stronger. Biofilms are also characterized by modified pH, nutrient scarcity, and osmolarity, making them tolerant to extremely harsh conditions. Therefore, getting rid of biofilms can be pretty challenging.
First of all, the slime-like substance secreted by biofilm microorganisms make it difficult for antibiotics to penetrate the structure. Besides, electrical charges on the biofilm surface often form a barrier that offers extra protection against antibiotics, making biofilms even harder to kill.
Since biofilms can tolerate antibiotics and it is also difficult to destroy them using disinfectants, they are considered a serious global health concern. This is exactly why it is so essential to know how biofilms work and develop ways to effectively get rid of them.
Biofilms Cause Numerous Infections
Another disadvantage of biofilms is that they cause numerous infections. While approximately 60% of nosocomial infections (healthcare-associated infections) are caused by biofilms, they also account for about 80% of the total number of microbial infections in humans.
A perfect example of a biofilm infection is dental plaque, an oral biofilm with a diverse microbial composition. While dental plaque can be removed, practicing good oral hygiene is essential to prevent biofilms from infecting your teeth.
Other common infections caused by biofilms include endocarditis, cystic fibrosis, meningitis, rhinosinusitis, periodontitis, osteomyelitis, and kidney infections. Biofilms may also account for non-healing chronic wounds and internal or external medical device-related infections
While biofilm infections heal slowly, they may not even heal at all as biofilms are pretty resistant to antibiotics. Therefore, biofilm infections can usually be treated by their removal.
Biofilms Are Often Responsible for Food Spoilage
In the food industry, the formation of biofilms often causes food spoilage and may even act as a source of public health problems caused by food-borne pathogens. While all food industry sectors can be affected by biofilms, this phenomenon is especially relevant to facilities processing dairy, fresh produce, poultry, red meat, and seafood.
As biofilms facilitate food spoilage, it is essential to eliminate biofilm formation in food processing facilities. Thus, when removing biofilms from the food processing environment, it is crucial to pay attention to the formulation and concentration of disinfectants as biofilms are pretty resistant to cleaning and sanitizing agents.
Biofilms are also involved in plant-based fermented foods. As microorganisms and their metabolites convert raw fruits and vegetables into final products, biofilms are often formed. While biofilms create favorable conditions for the cells to grow during industrial fermentation, they may also cause fermented food spoilage.
Biofilms Have a Negative Impact on Water Quality
Even though biofilms can be used for purifying water and treating soil and groundwater, they may also deteriorate water quality. This is because biofilms are eventually formed and developed on the interiors of water distribution systems. This process is also referred to as biological fouling.
As a matter of fact, biofilms can contaminate water, presenting a threat to public health, it is important to detect them early on. Unfortunately, water samples do not give sufficient information to locate and destroy biofilms. Therefore, all surfaces have to be examined thoroughly. Since biofilms are quite resistant to disinfectants, removing them from the surfaces is more effective than killing the cells.
As biofilms can cause severe infections, it is crucial to prevent water contamination at all costs. The key is to keep the equipment and water distribution systems clean while taking early biofilm detection and cleaning measures.