Spore-forming bacteria are a persistent concern in the food industry due to their ability to withstand harsh conditions and spoil various food products. These microorganisms, primarily from the Bacillus and Clostridium genera, are frequently implicated in the spoilage of bakery items, vacuum-packed meats, dairy products, and low-acid canned foods (André et al., 2017). Their resilient endospores can survive heat treatments, disinfectants, and other processing methods, making them formidable contaminants in food production (Wells-Bennik et al., 2016).
At CREM Co Labs, we specialize in identifying and mitigating these risks through advanced aerobic and anaerobic microbiological testing and tailored solutions.
Challenges in Managing Spore-Forming Bacteria
Spore-formers thrive in diverse conditions due to their resistance to environmental stresses, such as heat, acidity, salinity, and oxidative agents (André et al., 2017). Their ability to detect favorable conditions and germinate makes them particularly challenging to control (Wells-Bennik et al., 2016).
Economic and Health Impacts
- Economic Losses: Spoilage by non-pathogenic spore-formers is a significant burden for food manufacturers in North America.
- Canada: Food waste in Canada costs between $10 and $25 billion annually, an estimated $1 billion CAD annually is lost to food spoilage, with spore-forming bacteria being a major contributor (Canadian Food Inspection Agency, 2022).
- United States: Food spoilage costs are estimated at $10 billion USD annually, a substantial portion attributed to spore-forming bacteria (Grocery Manufacturers Association, 2015).
- Foodborne Diseases: Pathogenic spore-formers such as Bacillus cereus, Clostridium perfringens, and Clostridium botulinum are responsible for severe foodborne illnesses (Wells-Bennik et al., 2016).
- Canada: Approximately 4 million cases of foodborne illness occur annually, with spore-formers contributing a significant share (Public Health Agency of Canada, 2022).
- United States: Foodborne diseases cause 48 million illnesses, 128,000 hospitalizations, and 3,000 deaths annually. Spore-forming bacteria are major culprits in outbreaks linked to improperly processed foods (Centers for Disease Control and Prevention, 2021).
Industry Trends and Challenges
- Minimal Processing: Consumer demand for fresh, minimally processed foods creates an environment conducive to spore germination and growth (André et al., 2017).
- Packaging Innovations: The shift from metal to heat-resistant plastic packaging increases the survival of heat-resistant spores (Wells-Bennik et al., 2016).
- Preservative Reduction: Pressure to reduce chemical preservatives can result in insufficient control measures for spore-formers (André et al., 2017).
- Emerging Contaminants: New species with enhanced resistance profiles are being identified, posing additional challenges to food safety protocols (Wells-Bennik et al., 2016).
Importance of Proactive Management
Understanding the biology and ecological role of spore-forming bacteria is crucial for effective management. Food processors must adopt a multi-faceted approach, leveraging both traditional and innovative methods to minimize spoilage and foodborne illnesses (André et al., 2017).
Key Spore-Forming Bacteria and Their Impacts
- Bakery Products: Spoiled predominantly by Bacillus amyloliquefaciens, leading to changes in texture and odor (André et al., 2017).
- Meat Products: Contamination by Clostridium species often affects refrigerated, vacuum-packed meats (André et al., 2017).
- Milk and Dairy Products: Even heat-treated products (pasteurized or sterilized) are susceptible to Bacillus and Clostridium spores, depending on storage conditions (André et al., 2017).
- Canned Foods: Low-acid canned foods are prone to spoilage by heat-resistant bacteria such as Geobacillus stearothermophilus and Moorella thermoacetica (Wells-Bennik et al., 2016).
Mechanisms of Food Spoilage
Food spoilage occurs when spores germinate and grow under favorable conditions, such as appropriate temperature and nutrient availability. This leads to undesirable changes in food properties, including texture breakdown, off-odors and flavors, gas production, and pH shifts (André et al., 2017).
Advanced Control Strategies
Preventing foodborne disease and spoilage requires a multi-faceted approach. Emerging solutions include:
- Source Control: Identifying and eliminating contamination at its origin (Wells-Bennik et al., 2016).
- Innovative Processing: Combining heat treatments, pH adjustments, and natural preservatives to inhibit spore germination (André et al., 2017).
- Genomic Insights: Leveraging whole-genome sequencing to understand spore resistance and growth triggers (Wells-Bennik et al., 2016).
CREM Co Labs: Your Partner in Food Safety
At CREM Co Labs, we are committed to helping food manufacturers combat spore-forming bacteria. Our ISO 17025-accredited laboratory offers:
- Comprehensive Testing: Detection, enumeration, and identification of aerobic and anaerobic spore-formers.
- Tailored Solutions: Strategies to reduce contamination, validate processing methods, and extend product shelf life.
- Advanced Molecular Tools: Cutting-edge genomic techniques to assess resistance profiles and optimize food safety interventions.
By partnering with us, you gain access to expertise that ensures your products meet the highest safety standards, helping you mitigate risks and maintain consumer trust.
Future Directions
Ongoing research into spore-forming bacteria will enable even more effective strategies, including enhanced detection methods to identify uncultivable spore-formers, deeper insights into sporulation and germination to refine predictive models, and multidisciplinary approaches that integrate molecular biology, food science, and omics technologies (André et al., 2017).
Main species responsible for spoilage of different food types and their physiological characteristics. (André et al., 2017).
| Food | Species | Growth temperature and pH range | Heat resistance (D value) |
| Bakery products and aerobic flora | Bacillus amyloliquefaciens | 15 °C to 50 °C, opt. 30–40 °C | 2,5 min at 110 °C, z = 12,8 °C 2,1 min at 115 °C, z = 7,4 °C |
| Refrigerated vacuum-packed meats | Clostridium algidicarnis | >4 to 37 °C, opt 25–30 °C | 230 min at 90 °C, z = 10,5 °C 5 min at 95 °C |
| Clostridium putrefaciens | <5 à 30 °C opt 15–25 °C <0 °C–<37 °C |
14 min at 80 °C | |
| Clostridium estertheticum | 1 °C to 15 °C | 48 s à 100 °C | |
| Clostridium gasigenes | −1,5 à 26 °C, opt 20–22 °C | No data available | |
| Pasteurized milk | Bacillus | No type species | |
| Paenibacillus | |||
| Sterilized milk | Bacillus sporothermodurans | 0 to 50 °C | 6 s at 140 °C |
| Dehydrated milk | Geobacillus stearothermophilus | 40 to 70 °C, pH mini 5,0n | 3 min at 121 °C, z = 9.1 °C T5D < 0,5 min to 12,1 min at 120 °C |
| Anoxybacillus flavithermus | 43 to 62 °C, opt 57 °C | 2 min at 110 °C, z = 13 °C | |
| Fermented milk | Clostridium tyrobutyricum | <25 to 45 °C, opt 30–37 °C <12–15 °C to 40.2–43.3 °C |
0,053 min at 120 °C, z = 14,5 °C |
| Clostridium butyricum | 8–11 °C-NDs 10 °C-ND opt 30–37 °C |
0,045 min at 120 °C, z = 11,7 °Cr 4,7 min 100 °C |
|
| Clostridium sporogenes | <25 to >45 °C, opt 30–40 °C | 1,28 min at 121 °C, z = 11,1 °C | |
| <11°C-NDv | 0,8 to 2,2 min at 105 °C, z = 6,6–7,8 °C | ||
| Clostridium beijerinckii | 25 à 45 °C opt 37 °C | No data available | |
| Acidic canned foods | Alicyclobacillus acidoterrestris | <35°C–>55 °C 25°C–60 °C pH 2.2–5.8 |
1.7 min at 95 °C, z = 7.6 °C 2.3 min at 102 °C |
| Moderately acidic canned foods | Clostridium pasteurianum | pH limit: 3,5 or 4,3 | 1,9 to 4,31 min at 100 °C, z = 5,05 to 10,8 in food 4,4 min at 90 °C, z = 11 °C 13,6 min à 90 °C, 3,8 min at 95°C |
| Bacillus coagulans | <30 to <61 °C, opt 40–57 °C, pH limit 4.0 30 °C to 55 °C |
1.1 to 92,3 min at 110 °C, z = 6,8 to 9,6 °C 0,05 to 38,6 min à 110 °C, z = 8,3 to 5,7 °Cc |
|
| Low acid canned foods | Geobacillus stearothermophilus | 40 to 70 °C, pH mini-5,0 | D = 3 min at 121 °C, z = 9.1 °C T5D < 0,5 min to 12,1 min à 120 °Cn |
| Moorella thermoacetica | 1 to 65 °C, pH mini-5,7 | D = 1–10 min at 130 °C | |
References
- André, S., Vallaeys, T., & Planchon, S. (2017). Spore-forming bacteria responsible for food spoilage. Research in Microbiology, 168(4), 379-387. https://doi.org/10.1016/j.resmic.2016.10.003
- Wells-Bennik, M. H. J., et al. (2016). Bacterial Spores in Food: Survival, Emergence, and Outgrowth. Annual Review of Food Science and Technology, 7, 457–482.
- Canadian Food Inspection Agency. (2022). Economic impacts of food spoilage in Canada.
- Grocery Manufacturers Association. (2015). Cost of food spoilage in the U.S.
- Public Health Agency of Canada. (2022). Annual report on foodborne illness in Canada.
- Centers for Disease Control and Prevention. (2021). Estimates of foodborne illness in the United States.