Biofilm and why we should talk about it

Image of a biofilm developing

Miss them and they will cause trouble: Why we need to start talking about biofilms

What may look like clean food processing equipment could be covered in invisible bacterial colonies. Here’s how to maintain cleanliness and safety at your facility.

“I don’t see any biofilm in my facility, so it must not be a problem.” If that’s what you’re thinking, it’s worth taking a closer look. Biofilms tend to hide in the less visible bends and creases of your equipment. They’re often difficult to find, but they should never be ignored. If unaddressed, they can lead to serious – and costly – problems, including product spoilage, extra downtime for troubleshooting or even product recalls, reprocessing and food waste.

Let’s look at what biofilms are, how to detect them and how to reduce your risks.


A city of microbes

A biofilm is defined as a complex, structured community of bacteria and other microorganisms attached to a surface. These microorganisms undergo changes which enable them to survive and thrive in environments normally considered hostile. Biofilms can form on just about any type of surface, including your teeth or your toothbrush. In a food and beverage processing facility, we typically associate biofilms with drains, but they also can be found on filters, poorly designed equipment, uncleanable steam ports, air blow lines or other difficult to clean or infrequently cleaned surfaces. The common denominator of all these locations is: wet surfaces that contain nutrients, paired with insufficient and infrequent hygiene interventions.

Biofilm forms when microorganisms adhere to a surface. They do this typically to access nutrients. As these microorganisms replicate and form a colony, they create a protective barrier made up of mostly proteins and complex polysaccharides. This protective barrier increases the microorganisms’ resistance to cleaning and disinfection. Moreover, the organized biofilm regulates its inhabitants across different strains for example to generate extracellular enzymes that can digest nutrients and make growth factors available for cell propagation. In general, the biofilm reacts to all sorts of environmental factors (like temperature, pH-level, water activity, oxygen presence) to protect itself but also to benefit from the habitat as much as possible.

Signs you may have a biofilm risk

It’s a common misconception that if you don’t see biofilms on your surfaces, then you don’t have a biofilm problem. Biofilms typically propagate within nooks, crannies and hard-to-reach areas – no wonder they are hard to detect. Once they attach to a surface, they not only continue to grow, but they also become more resistant to the things that normally kill them, like heat or chemicals.

The following are signs that you may have a biofilm in your facility:

  • Positive ATP-bioluminescence test results: Adenosine triphosphate (ATP), is an indicator of life. Although it is not direct proof, but where there is ATP, there might also be a biofilm.
  • Micro-status testing: Sporadic quality failures, presence of pathogens like Listeria subspecies or spikes in microbiological counts could be due to biofilms
  • Odor: A foul or sour smell is often an indicator of biofilms’ appearance.
  • Visual: Biofilms’ looks can range from slight equipment discoloration to a slimy/ sticky substance attached to a surface. Variable UV-light and indicator dyes can help to make biofilm and organic residues visible. Ecolab has selected a range of indicators that is readily available and widely accepted in field testing.
Text explaining the process of how a biofilm forms

Ways to reduce biofilm risk

Without realizing it, you may be creating environments conducive to biofilm growth. If you find biofilm activity, your best bet is to take a holistic and systematic approach to address it. Ecolab has established a four-step approach to biofilm control which includes a defined product and service offering. The most effective and preventive way to reduce biofilm formation is making sure your facility has a sound and validated hygiene plan. However, you still may find challenges due to:

  • Lack of hygienic design: Ensure all equipment is designed to be cleanable, without dead legs (i.e., areas that see little flow) or porous surfaces. If necessary, modify your equipment so it can be easily cleaned and disinfected. (See Hygienic Design blog)
  • Insufficient preventive maintenance: Conduct preventive maintenance according to schedule. Biofilms can hide in harbor points like gaskets and valves. Adhering to your maintenance schedule is a good way to keep biofilm growth at bay.
  • Lack of training: Create and maintain a non-negotiable, robust master cleaning and disinfection plan. Then stick to it no matter what and make sure your employees are doing what they have learned. Rapid hygiene outcome testing using ATP or Protein swabs establishes KPIs that your operators can work against. Working against clear targets is much easier and more rewarding that cleaning against invisible or even moving targets. In particular, the cleaning regimes for food safety critical surfaces should be validated. This way cleaning procedures become non-negotiable, even when you have new staff, a tight schedule or when you are on deadline.

To learn more about how Ecolab’s four steps to biofilm control can help you mitigate your food safety and quality risks, contact your local Ecolab team member or contact us here.

About the Author

Image of Thomas Buehler

Dr Thomas Buehler

Technical Excellence Specialist for Food & Beverage

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