Following on from the importance of microbial strain selection in cleaning, one of the most valuable specialist applications of such technology is the treatment of fat oil and grease build-up. In kitchens, drains and food processing areas, accumulated grease deposits can become a serious operational problem.
When not effectively treated, fat oil and grease residues can cause blocked drains, persistent odours, reduced hygiene standards and costly maintenance issues.
By selecting Bacillus strains with strong lipase-producing capabilities, probiotic cleaning systems can break down grease deposits at source, helping maintain cleaner drains and more efficient kitchen environments.
What Is Fat Oil and Grease?
The term fat oil and grease refers to lipid-rich residues that enter drainage systems and accumulate on surfaces over time.
Common sources include:
- Cooking oils
- Animal fats
- Butter and dairy residues
- Food preparation waste
- Greasy wash water
- Process residues in food manufacturing environments
Once cooled or deposited, these materials adhere to surfaces and pipework, creating stubborn build-up.
Why Fat Oil and Grease Provides a Major Cleaning Challenge
Unlike water-soluble residues, fat, oil and grease (FOG) can solidify, adhere strongly to surfaces and trap other debris. This makes FOG particularly difficult to remove once it has accumulated within drains, pipework and sewer systems.
The problem can be further intensified when calcium salts naturally present in flush water, wastewater or drain environments react with FOG deposits. This reaction can form calcium-bound FOG, often referred to as cFOG. These calcium–fat complexes are highly insoluble, hard, sticky and persistent, making them much more difficult to break down or remove than fresh grease deposits.
Over time, FOG and cFOG accumulation can lead to:
• Drain blockages
• Restricted water flow
• Hard, insoluble grease deposits
• Biofilm formation
• Persistent malodours
• Increased cleaning and maintenance costs
• Formation of large sewer obstructions, commonly referred to as fatbergs
FOG accumulation is widely recognised as a major contributor to sewer and drain blockage events globally. Once converted into insoluble calcium-bound deposits, the material can continue to build up with wipes, paper, grit and other debris, contributing to the formation of fatbergs within sewer networks.
Why Bacillus Is Effective for Fat, Oil and Grease Treatment
Selected Bacillus strains are highly effective in fat, oil and grease management because they secrete extracellular enzymes that are specifically suited to lipid degradation, including:
• Lipases
• Esterases
These enzymes are released directly into the surrounding environment, where they act on the surface of FOG deposits and begin breaking down complex fats, oils and greases into smaller, more biodegradable components.
Importantly, FOG residues are not all the same. Their composition can vary depending on the source of the material, such as animal fats, vegetable oils, cooking residues, emulsified greases, soaps or calcium-bound FOG deposits. Carefully selected Bacillus strains can produce the appropriate lipase and esterase enzyme profile needed to break down the specific composition of these fat residues.
This means the treatment is not simply displacing or softening the grease. The Bacillus strains continue to biologically degrade the residue over time, provided suitable moisture, nutrients and environmental conditions are present. Through natural biodegradation pathways, the FOG material is progressively broken down into simpler end products, ultimately carbon dioxide, water and microbial biomass.
Why Strain Selection Matters
Not all Bacillus strains produce the same enzymes, or produce them at the same level. Effective FOG treatment depends on selecting strains with:
• High lipase activity
• Strong esterase production
• Enzyme profiles suited to the target FOG composition
• Reliable performance in wet, contaminated drain and wastewater environments
• Consistent biological activity over time
A generic bacterial blend may offer only limited benefit if the strains do not produce the correct enzyme profile for the specific FOG residues present. In contrast, a targeted Bacillus consortium can deliver a more effective and sustained breakdown of fat, oil and grease by combining strains with complementary enzyme activity and proven performance in real drain, grease trap and wastewater conditions.
Ideal for Drains and Kitchen Environments
Drains and kitchens create harsh, variable conditions that can reduce the performance of many cleaning technologies.
Selected Bacillus spores are particularly valuable because they are resilient under:
- Variable pH conditions
- Changing temperatures
- Moisture fluctuations
- Exposure to surfactants found in cleaning products
Their spore-forming nature also supports product stability and allows activation when environmental conditions become favourable.
Breaking Down Established Grease Deposits
One of the biggest challenges with FOG build-up is that deposits often form structured layers or become incorporated into biofilms.
Carefully selected Bacillus strains can interact with these established deposits, enabling microbial activity within the grease layer itself. This supports:
- Degradation of accumulated fats
- Improved drain cleanliness over time
- Reduced recurrence of blockages
- Better long-term hygiene performance
Fat, Oil and Grease and Malodour Reduction
Grease deposits are also a major source of unpleasant drain and kitchen malodours. This is because fat, oil and grease residues do not just sit passively in drains. Over time, naturally occurring bacteria already present in the drain environment begin to break down fat molecules.
In simple terms, fats and oils are made up of long-chain fatty acids attached to a glycerol backbone. When native drain bacteria partially degrade these fats, they can release smaller volatile fatty acids, such as butyric, valeric and other short-chain fatty acids. These compounds are called “volatile” because they readily evaporate into the air, where they are detected as unpleasant rancid, sour, cheesy or sewage-like odours.
The problem is that natural drain bacteria often only partially degrade the fat residues. This incomplete breakdown can release odorous volatile fatty acids faster than they are further degraded, allowing smells to build up within drains, grease traps and surrounding kitchen areas.
Selected Bacillus strains help address this by producing enzymes that support a more complete degradation pathway. Lipases and esterases first break larger fat molecules into smaller fatty acid components. The Bacillus strains can then continue metabolising both the long-chain fatty acids and the smaller volatile fatty acids, progressively converting them through natural biodegradation into simpler end products such as carbon dioxide, water and microbial biomass.
By reducing the grease layer, removing trapped organic matter and degrading the volatile fatty acids responsible for bad smells, Bacillus-based systems help control malodour at source rather than simply masking it with fragrance. This supports cleaner, fresher kitchen, drain and grease-management environments.
Applications for Fat, Oil and Grease Control
Targeted Bacillus formulations are ideal for:
- Commercial kitchens
- Food service drains
- Grease traps
- Food manufacturing washdown areas
- Catering facilities
- Hospitality environments
Wherever grease accumulation is a recurring issue, biological treatment can provide ongoing support.
Conclusion
Effective management of fat, oil and grease requires more than surface cleaning or temporary grease displacement. FOG deposits are complex, persistent and can become increasingly difficult to remove once they solidify, bind with calcium salts or trap additional organic debris. For this reason, successful FOG control depends on targeted biological degradation, supported by carefully selected Bacillus strains with the right enzyme capability.
By choosing Bacillus strains with strong lipase and esterase production, probiotic cleaning systems can:
• Break down FOG deposits at source
• Degrade long-chain fatty acids and odour-forming volatile fatty acids
• Support cleaner drains, pipework and grease-management systems
• Reduce the risk of blockages, restricted flow and fatberg formation
• Help control malodours at source rather than masking them
• Improve long-term cleanliness and hygiene standards
• Lower reliance on harsh chemical treatments
As a result, Bacillus-based solutions offer a smarter, more sustainable and scientifically targeted approach to managing fat, oil and grease in drains, kitchens, food-service areas and food-processing environments. Instead of simply moving the problem further down the system, they support the progressive biological breakdown of grease residues into simpler end products such as carbon dioxide and water.