Biofilms in the Dairy Industry: An Invisible Enemy at the Table

In the dairy industry, biofilm formation is directly related to the microbiological safety of products, representing a silent challenge that affects everything from production to the final quality of what we consume.

Food Safety Microbiology Contamination

The Microbial Metropolis

Imagine a microscopic city, with roads and canals, where millions of bacteria live protected by an almost impenetrable fortress. This is not a scene from a science fiction movie, but the reality of biofilms that form daily on equipment in the dairy industry. These bacterial communities are responsible for significant economic losses and represent a constant risk to food safety1 .

Economic Impact

Biofilms cause equipment corrosion, reduced heat transfer efficiency, increased energy consumption, and frequent part replacements2 .

Health Risks

Up to 60-80% of microbial infections in the human body are related to these bacterial structures.

What Are Biofilms and How Do They Develop?

The Organized Ecosystem

Biofilms are much more than simple bacterial clusters - they are organized ecosystems where microorganisms form complex communities, creating channels that allow the passage of nutrients, metabolites, and waste2 .

Biofilm Composition

Why Dairy Industry is Attractive for Biofilms

The organic load present in the dairy industry, with high concentrations of proteins and fats, as well as the concentration of microorganisms, are factors that strongly predispose biofilm formation3 .

Low Risk High Risk

Dairy Industry Biofilm Risk: High

The Five Stages of Building a Bacterial Fortress

1. Pre-adhesion

Organic food molecules, such as milk residues, form a conditioning film on surfaces, essential for primary microorganisms to adhere2 .

2. Reversible Adhesion

Bacterial cells are attracted to bind to the conditioning film, depending on structures such as fimbriae and pili to aggregate2 .

3. Irreversible Adhesion

Microorganisms begin to multiply and form cellular aggregates, activating genes involved in cellular communication and production of exopolysaccharides2 .

4. Maturation

The structure reaches maturity with increased population density and production of exopolysaccharides to increase biofilm thickness and stability2 .

5. Detachment

Cells become mobile again, detaching from the biofilm and potentially contaminating food or forming new biofilms in the production line2 .

A Portrait of Diversity: Experiments Reveal Bacterial Composition in Dairy Biofilms

Research Methodology

A crucial study to understand the real threat of biofilms in the dairy industry investigated the bacterial composition that forms on equipment surfaces during processing5 .

  • Cultivation-independent methods: Using Illumina MiSeq sequencing to identify non-cultivable microorganisms in the laboratory.
  • Cultivation-dependent methods: Traditional microbiological culture techniques to isolate and identify cultivable species.
Biofilm Quantification

To determine the biofilm-forming capacity of the identified bacteria, researchers performed analyses through crystal violet staining, a method that allows quantification of the biomass of formed biofilms5 .

Results: An Unexpected Ecosystem

The results revealed much greater bacterial diversity than imagined. High-tech sequencing identified5 :

8

Bacterial Phyla

18

Identified Species

18

Detected Genera

8

Species by Culture Method

Comparison Between Bacterial Identification Methods in Dairy Biofilms
Parameter Illumina Sequencing Culture Method
Species Identified 18 8
Bacterial Phyla 8 Not determined
Detected Genera 18 8
Ability to Detect Non-cultivable Microorganisms Yes No

Biofilm-Forming Bacteria in Dairy Equipment

Bacterial Species Biofilm Formation Capacity Pathogenic Potential Risk Level
Acinetobacter baumannii Yes Opportunistic Medium
Acinetobacter junii Yes Opportunistic Medium
Enterococcus faecalis Yes Foodborne High
Corynebacterium callunae Yes Opportunistic Medium
Stenotrophomonas maltophilia Yes Opportunistic Medium
Analysis and Significance of Results

The importance of these results lies in the finding that most of the identified bacteria are opportunistic pathogens or foodborne, which provides crucial guidance for quality control of products produced in dairy processing units5 .

The disparity between traditional detection methods and modern sequencing techniques suggests that food safety protocols based solely on culture methods may be significantly underestimating the actual microbial risks present in production lines.

Prevention and Control Strategies: The War Against Biofilms

Physical Methods
  • Manual cleaning with equipment disassembly
  • Ultrasound application
  • Ultraviolet radiation
  • Air or gas injection
  • Thermal shocks
Chemical Methods

Chemical methods involve the application of substances with antimicrobial, surfactant, and dispersant properties, whose mechanism of action occurs by weakening the polymeric matrix of biofilms and weakening biofilm interactions2 .

Alkaline Detergents

Acidic Detergents

The Importance of Hygiene Protocols

To control biofilm formation, hygiene methodologies and chemical agents that promote the necessary safety and efficacy must be selected3 . Hygiene should be divided into two defined stages2 :

1. Cleaning

Aims to remove organic and inorganic residues adhered to surfaces, consisting mainly of proteins, carbohydrates, lipids, and mineral salts.

85% Effective
2. Sanitization

Indispensable procedure after cleaning, since the number of microorganisms present is still high even after removal of visible residues.

95% Effective

New Detection Technologies

Early detection is crucial in biofilm control. Modern methods include:

Aseptic Sampling

Systems for aseptic and representative sampling

Plate Counts

Standard plate counts and laboratory pasteurized counts

UV Detection

Portable UV emission devices that expose bacteria and fungi trapped on the surface

Conclusion: A Challenge That Requires Constant Vigilance

The formation of biofilms on different materials used in the milk processing industry represents a complex technological and microbiological challenge that requires multidisciplinary approaches for its effective control. With considerable economic losses and serious risks to consumer health, this invisible enemy demands constant vigilance and permanent technological updating.

The dairy industry lives the paradox of working with a nutritious and highly perishable product that, while feeding millions, can become the ideal environment for the development of resistant microbial communities. The path to effective control passes through understanding the mechanisms of biofilm formation, implementing rigorous hygiene protocols, and adopting advanced detection technologies.

As demonstrated by the genetic sequencing study, our ability to identify the true inhabitants of these microbial communities is still evolving, suggesting that much remains to be discovered about this microscopic universe that inhabits our food industries. The war against biofilms is far from over, but each scientific advance represents a new weapon in this battle for food safety.

References