Questions about the use of enzymatic cleaners for control of Listeria monocytogenes were among the most asked questions during and following Vikan’s Listeria control webinar. The topic was only briefly discussed in the webinar but both Nicola Wilson (of Samworth Brothers) and Dr. John Butts (of Food Safety by Design), mentioned having seen some success with enzymes.
I, myself, was skeptical of enzymatic cleaners and expressed as much in discussion during our panelists’ coordinated response to the overflow Q&A. Dr. Butts pushed back. He asked me, “Jack, have you ever used an enzymatic cleaner in a plant? Those of us that have, have found them very useful.” I like to imagine that he then called me a ‘whippersnapper’ but opted not to type that into the email.
Touché, Dr. Butts. When the "father of seek-and-destroy" himself questions your experience with the very topic you're debating, the only honest answer is "Not nearly enough to be this confident about it." Admittedly, my concerns about enzymatic products are also somewhat academic and were reinforced only by my own few underwhelming experiences with their use.
At the root of our disparate experiences is, ironically, the first of my three main concerns surrounding enzymatic cleaners. That is, calling a cleaner “enzymatic” is about as specific as calling someone “outdoorsy”; it could mean that they summited Everest for fun or that they once sat on a patio. The term encompasses such a vast range of formulations, mechanisms, and efficacy levels that meaningful evaluation becomes nearly impossible without diving into specifics.
So, let’s do exactly that. I want to break down the major categories of enzymatic cleaners to establish some clarity, then revisit my remaining two concerns with proper context. Spoiler alert: once you separate the wheat from the chaff, my concerns start looking a bit overblown. By the end, you’ll see that I’ve softened my formerly hardline stance against enzymatic cleaning products for Open Plant Cleaning (OPC).
Types of Enzymatic Cleaners
Any commercially available enzymatic product is actually going to be a blend of multiple enzymes (Stiefel et al., 2016). These enzymes fall into several broad categories: proteases, polysaccharidases (of which cellulases and amylases are most prevalent), lipases, and DNases.
Proteases catalyze the breakdown of proteins. Proteins are, generally, the most structurally important component of mature biofilms (Pant et al., 2023). For that reason, proteases show promise for the treatment of biofilms. One study found that a polysaccharidase/protease treatment combination was most effective. However, both enzymes can’t be active at the same time to work effectively. Delayed activation of the protease was achieved by immobilizing the protease within alginate beads (Orgaz et al., 2007).
Cellulases, which catalyze the breakdown of cellulose, have shown promising results against biofilms formed by Pseudomonas spp. (Jayasekara & Ratnayake, 2019). Cellulose is but one of several possible exopolysaccharides produced by Pseudomonas spp. and, unsurprisingly, was only found to be effective against mixed-species biofilms whose EPS was heavy in polysaccharide content (Fanaei Pirlar et al., 2020).
Amylases represent another major group of polysaccharide-digesting enzymes. Currently, amylases hold about 25% of the global market share of cleaning enzymes (Gonçalves et al., 2020). α-Amylase has shown promise in removing biofilms formed by Staphylococcus aureus and P. aeruginosa (Fleming & Rumbaugh, 2017). Amylase production is also thought to be the causative explanation for the competitive exclusion of other biofilm-formers by Bacillus subtilis (Lahiri et al., 2021).Lipases are enzymes that catalyze the breakdown of lipids (fats). In searching the literature I found very little published research supporting their efficacy and practically none in the context of multi-species biofilms (Pant et al., 2023). Supporting data may exist in proprietary form since there are many commercial products available.
In contrast, a plethora of published data supports the biofilm-prevention efficacy of DNases; the enzymes that break down extracellular DNA (eDNA). eDNA plays an important role in the attachment stage of biofilm formation and structural stability of the extracellular polymeric substance (EPS) matrix in several bacterial species including L. monocytogenes (Jang & Eom, 2020; Tang et al., 2013; Voglauer et al., 2025; Wang et al., 2023; Zetzmann et al., 2015). That abundance of promising data hasn’t translated to use in the industry due to their impracticality and expense (Brown et al., 2015; Karygianni et al., 2020).
Evaluating Enzymatic Cleaners
From all I’ve gathered, the efficacy of enzymatic cleaning products might be different depending on the structural and compositional makeup of the EPS. This, in turn, is dependent on the interplay between the microbiome and its microenvironments (Wang et al., 2023). It is entirely possible that an enzymatic product that you’ve seen work in one plant will fail in another; in fact, I’d say it’s likely. As such, there are two prudent steps to take when evaluating an enzymatic product:
- Find out what enzyme(s) are part of the formulation and do a little research on their pH and temperature requirements; are they reasonable for your application?
- Try it out in your facility.
With this enzymatic landscape mapped out, let me address my remaining two concerns about enzymatic cleaners in OPC applications, both of which proved less problematic than I initially thought.
The Importance of Process
My second concern was straightforward: enzymes break down organic matter into smaller, more bioavailable nutrients. Since bacteria evolved to produce these very enzymes to feed themselves, wouldn't adding enzymatic cleaners essentially be serving bacteria a pre-digested meal? This concern isn't entirely unfounded. Enzyme action does generate breakdown products that could theoretically serve as carbon sources for surviving bacteria.
However, this risk is largely mitigated in properly executed OPC protocols. Effective enzymatic cleaning should be part of a comprehensive cleaning sequence that also includes physical removal of soils, alkaline cleaning, rinsing, and biocide application.
The real risk comes from incomplete sanitation; enzymes being used without proper follow-up sanitization or that are left to act in a residual manner. This constitutes my third concern; enzymatic biofilm disruption releases viable bacteria in a delayed manner and therefore without immediate application of a biocide.
This is where my initial assumptions about enzymatic cleaners led me astray. I had erroneously assumed that all OPC enzymes required the same extended contact times as CIP applications (typically an hour or more of circulation (Pant et al., 2023)). Under those assumptions, the liberation concern becomes paramount; you'd have viable Listeria cells floating freely for extended periods before any sanitization step.
However, learning that fast-acting cleaning enzymes like amylases can work effectively within minutes (before their solution temperature drops below optimal levels) changes the risk-benefit calculation entirely. Fast-acting formulations can disrupt biofilm matrices and be followed immediately by sanitization, minimizing the window where liberated bacteria pose a dispersal risk. The key insight is that enzymatic cleaning for OPC applications should prioritize speed over extended contact time. This requires selecting enzyme formulations designed for rapid action at the temperatures achievable in open plant environments, not the sustained high-temperature conditions possible in CIP systems.
Temperature control represents both a limitation and an opportunity for enzymatic cleaners in OPC. Most enzymes have narrow temperature ranges: too cold and reaction rates plummet, too hot and the enzyme denatures. In open plant environments, maintaining precise temperatures is challenging. However, this limitation forced me to reconsider my assumptions about enzymatic cleaning timelines. Rather than viewing temperature sensitivity as a deal-breaker, it becomes a design constraint that drives formulation toward fast-acting enzymes that can accomplish their work within the temperature window available during application.
Modern enzymatic formulations for OPC are increasingly designed around this reality, incorporating enzyme variants selected for activity at lower temperatures or rapid action before cooling occurs. Some products also include temperature-stabilizing additives or encapsulation technologies that extend the effective working time.
A New Perspective
Understanding these nuances has genuinely changed my perspective on enzymatic cleaners for OPC applications. When properly formulated for rapid action and integrated into comprehensive cleaning protocols, enzymes can indeed be valuable tools against environmental biofilms and Listeria persistence. The key is that not all enzymatic cleaners are created equal, and not all applications are appropriate for enzymatic approaches.
Success requires matching the enzyme system to the specific biofilm composition, environmental constraints, and operational timeline of your facility. For facilities struggling with persistent Listeria environmental contamination, particularly in areas where traditional cleaning approaches have proven insufficient, enzymatic cleaners represent an additional arrow in their quiver. Sure, an arrow isn’t a silver bullet, but when used strategically as part of a comprehensive seek-and-destroy approach, enzymes can enhance the effectiveness of existing protocols.
Dr. Butts was right to push back on my blanket skepticism. Sometimes experience trumps theory, and sometimes whippersnappers like me need to listen more and assume less. I’m officially eating my words, which would probably be more digestible if I treated them with some amylase first.
Sources:
Brown, H. L., Hanman, K., Reuter, M., Betts, R. P., & Van Vliet, A. H. M. (2015). Campylobacter jejuni biofilms contain extracellular DNA and are sensitive to DNase I treatment. Frontiers in Microbiology, 6. https://doi.org/10.3389/fmicb.2015.00699
Fanaei Pirlar, R., Emaneini, M., Beigverdi, R., Banar, M., B. Van Leeuwen, W., & Jabalameli, F. (2020). Combinatorial effects of antibiotics and enzymes against dual-species Staphylococcus aureus and Pseudomonas aeruginosa biofilms in the wound-like medium. PLOS ONE, 15(6), e0235093. https://doi.org/10.1371/journal.pone.0235093
Fleming, D., & Rumbaugh, K. (2017). Approaches to Dispersing Medical Biofilms. Microorganisms, 5(2), 15. https://doi.org/10.3390/microorganisms5020015
Gonçalves, S., Lee, S., Mousavi Khaneghah, A., & Oliveira, C. (2020). Enzyme-based approaches to control microbial biofilms in dairy processing environments: A review. Quality Assurance and Safety of Crops & Foods, 12(SP1), 50–58. https://doi.org/10.15586/qas.v12SP1.828
Jang, H.-I., & Eom, Y.-B. (2020). Antibiofilm and antibacterial activities of repurposing auranofin against Bacteroides fragilis. Archives of Microbiology, 202(3), 473–482. https://doi.org/10.1007/s00203-019-01764-3
Jayasekara, S., & Ratnayake, R. (2019). Microbial Cellulases: An Overview and Applications. In A. Rodríguez Pascual & M. E. Eugenio Martín (Eds.), Cellulose. IntechOpen. https://doi.org/10.5772/intechopen.84531
Karygianni, L., Attin, T., & Thurnheer, T. (2020). Combined DNase and Proteinase Treatment Interferes with Composition and Structural Integrity of Multispecies Oral Biofilms. Journal of Clinical Medicine, 9(4), 983. https://doi.org/10.3390/jcm9040983
Lahiri, D., Nag, M., Sarkar, T., Dutta, B., & Ray, R. R. (2021). Antibiofilm Activity of α-Amylase from Bacillus subtilis and Prediction of the Optimized Conditions for Biofilm Removal by Response Surface Methodology (RSM) and Artificial Neural Network (ANN). Applied Biochemistry and Biotechnology, 193(6), 1853–1872. https://doi.org/10.1007/s12010-021-03509-9
Orgaz, B., Neufeld, R. J., & SanJose, C. (2007). Single-step biofilm removal with delayed release encapsulated Pronase mixed with soluble enzymes. Enzyme and Microbial Technology, 40(5), 1045–1051. https://doi.org/10.1016/j.enzmictec.2006.08.003
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