Natural Preservatives: Can These Bacteria Replace Chemicals in Our Food?
"Discover how Lactococcus lactis strains offer a safe, effective alternative to chemical preservatives for smoked sausages and other foods."
Food spoilage caused by bacteria and fungi is a widespread issue, leading to both economic losses and potential health risks from toxins produced by these microorganisms. While chemical additives and physical treatments have been used to combat spoilage, concerns about their safety have prompted a search for natural alternatives.
Lactic acid bacteria (LAB), particularly Lactococcus lactis, have emerged as promising biopreservatives. These bacteria, traditionally used in food fermentation, are recognized as safe and possess antagonistic properties against various microorganisms. This is due to their production of organic acids, diacetyl, bacteriocins, and low-molecular-weight substances with antifungal activity.
A study aimed to isolate and identify new antifungal Lactococcus strains and evaluate their potential use in preventing fungal spoilage. The research focuses on Lactococcus lactis strains that synthesize bacteriocins, antimicrobial peptides that can inhibit the growth of closely related bacteria and fungi. This approach offers a natural way to enhance food safety and reduce reliance on synthetic preservatives.
Nisin’s Food-Stabilizing Potential
A 2021 study evaluated the food-stabilizing potential of nisin Z produced by wild Lactococcus lactis subsp. lactis strains. The strains came from 114 raw milk and naturally fermented products and were identified by mass spectrometry before screening for the nisin Z gene. This work illustrates how raw and fermented foods can serve as sources of natural biopreservative candidates.
From Fermentation to Nisin
Lactococcus lactis has substantial economic importance because it is used extensively to produce fermented foods. Research summarized in the cited historical study indicates that the organism is widely held to have evolved from plant strains. Nisin, known for about five decades in the cited source, is a lanthionine-containing bacteriocin produced by certain Lactococcus lactis subsp. lactis strains.
How Can Lactococcus lactis Protect Food from Spoilage?
The research involved isolating Lactococcus strains from raw milk, dairy products, and fermented drinks like kurunga, kumiss, and Iranian "Dough" from various climatic regions. These sources were selected due to their historical use in preventing diseases, suggesting the presence of beneficial bacteria.
- Staphylococcus aureus
- Escherichia coli
- Pseudomonas aeruginosa
- Proteus vulgaris
- Salmonella gallinarum
- Aspergillus
- Fusarium
- Penicillium
- Rhodotorula
- Candida
New Bacteriocin-Producing Strains
A retrospective mini-review reports that Stoyanova and colleagues identified two promising bacteriocin-synthesizing strains, 194 and K-205. The strains were isolated from raw cow milk and kurunga from Buryatia. Another study found that bacteriocin 194-D production by Lactococcus lactis subsp. lactis 194-K occurred alongside producer growth, with maximum accumulation in the culture fluid after 14 to 20 hours.
Potential Versus Production Stability
Research on lactic acid bacteria isolated from artisanal Colonial-type cheese found that the isolates had bacteriocinogenic potential for use as food biopreservatives. This indicates that cheese-associated LAB may provide candidate organisms for natural preservation. However, separate work on Lactococcus lactis ssp. lactis CN1.10a from rusip reported unstable bacteriocin activity when production was performed in MRS broth at laboratory scale using 100 milliliters.
A Promising Future for Natural Food Preservation
The study's findings indicate that treating raw smoked sausages with Lactococcus lactis strains 194 and K-205 effectively inhibits the growth of spoilage microorganisms, extending shelf life while adhering to established quality standards. This suggests that Lactococcus lactis strains can potentially replace chemical preservatives, offering a safer and more natural approach to food preservation.
Clean-Label Demand and Nisin
A 2025 industry report describes increasing consumer demand for clean-label products and says many food companies are using natural preservatives such as Lactococcus lactis nisin. It presents this environmentally friendly antimicrobial peptide as a possible alternative to synthetic preservatives and chemical additives. A market report likewise describes nisin as a natural preservative extracted from Lactococcus lactis and links its growing acceptance to consumer preference for natural ingredients.
Building Safer Preservation Systems
A review of lactic acid bacteria presents LAB-based natural preservatives as a basis for improving food preservation. Its stated purpose is to provide theoretical support for their rational improvement and efficient application. The review connects this work with developing safer and more sustainable food-processing and preservation systems.
From Camel Milk to Fresh Beef
A 2026 study investigated two mixed LAB cultures, MCP1 and MCP2, composed of four Lactococcus lactis subsp. cremoris strains isolated from Algerian dromedary camel milk. The cultures were evaluated for biopreservative efficacy in fresh beef. The study reflects how strains from a specific traditional food environment are being examined for practical preservation applications.