Measuring endotoxins level in food and environnement

Food and water represent optimal conditions for bacterial development. While most bacteria do not represent any major threat to Man, the dangerous nature of some of them requires keeping an eye on what we are eating, but also what kind of product we give back to nature.

When discussing the toxicity of bacteria, the danger of endotoxins is often mentioned, and there is often a mix-up with lipopolysaccharides (LPS). It is important to note that not all lipopolysaccharides are harmful; in fact, many are non-toxic.

A good example is E. coli, one of the most common bacteria. Everyone has millions of E. coli in their gut microbiota, and they typically cause no harm. However, some strains can be dangerous due to the presence of toxic lipopolysaccharides on their outer membrane, which vary by serotype. For instance, Shiga-toxin-producing (enterohemorrhagic) E. coli O157:H7 is a serotype associated with food poisoning and is a leading cause of severe gastrointestinal disease in industrialized countries, posing a significant public health risk.

Therefore, the key is not to generalize all bacteria as harmful but to identify which ones are safe and which are not by analyzing their LPS structures. Thus, safety level could be determined before considering their removal.

Food safety is a priority. Determining the endotoxin content of foods is a key aspect of quality control, not just to check for their presence but to assess whether any present could be harmful if consumed. Therefore, providing accurate information about endotoxin levels in food is essential.

Every novel food derived from microbial fermentation must undergo validation by food safety authorities. In Europe, this is managed by the EFSA, while in the U.S., it’s managed by the Food and Drug Administration (FDA). These agencies evaluate the product’s origin, potential risks, and toxin levels.

To gain approval for a novel food, companies must conduct comprehensive toxicological studies to ensure the product’s safety. If the product is produced through Gram-negative bacterial fermentation, endotoxin testing is mandatory to confirm that levels remain within acceptable limits. Once these steps are completed, the application is submitted to the Commission for review.

Whether endotoxins originate from raw materials or contamination during production, maintaining control over their levels is crucial.

As mentioned earlier, the nature and quantity of endotoxins are important for food safety, but also for the environment. Effluents from industrial sites can be a potential source of endotoxins pollution for a nearby river or field, which can turn into a dangerous situation for humans and wildlife.

Also, airborne endotoxins can play a role as exogenous contaminants in the process. Therefore, controlled air environments are most often favored. Whether it is the final product that is contaminated, or the bioproducts/reagents/raw materials that end up in the process effluent, it is important to regularly monitor the production lines to ensure that no unwanted endotoxins are released into the production process.

These contaminations occur regularly, such as residual endotoxins stuck in filtration systems (in heparin columns, for example) which might lead to cross contamination with your final product. Sometimes neither high temperatures nor lasers are sufficient to remove these residual endotoxins. It is also necessary to distinguish between residual lipopolysaccharides from contaminations and potential endotoxins of interest in the product.

From both a safety and regulatory perspective, exposure to contamination can be a major issue. Identifying the nature of endotoxins at different stages of the process can help locate the source of the contamination and provide the appropriate information to resolve the problem.