Sauerkraut is a staple fermented vegetable dish enjoyed around the world. It is made by shredding cabbage and mixing it with salt, then allowing the natural bacteria present on the cabbage leaves to ferment the mixture. This results in a tangy, sour flavor that is a favorite in many cuisines.
However, not all bacteria present in sauerkraut fermentations are beneficial. Just like in any bacterial ecosystem, there are organisms that can have a negative impact on the quality and safety of the final product. One group of microorganisms that are of particular concern in sauerkraut fermentations are bacteriophages, viruses that infect and replicate within bacterial cells.
Understanding the ecology of bacteriophages in sauerkraut fermentations is essential for developing strategies to control their populations and ensure consistent, high-quality products. In a recent study published in the journal Applied and Environmental Microbiology, researchers investigated the phage ecology present in commercial sauerkraut fermentations.
The study found that there were at least 26 distinct phages present in the commercial sauerkraut fermentation tanks sampled. These phages belonged to either the family Myoviridae or Siphoviridae, and showed distinct host ranges and DNA fingerprints.
The researchers also isolated and identified 28 distinct host strains of lactic acid bacteria (LAB) present in the fermentations. These included Leuconostoc, Weissella, and Lactobacillus species. The host strains were identified using restriction analysis of the intergenic transcribed spacer region and 16S rRNA sequence analysis.
Interestingly, the study found that there were two different phage-host systems present in the fermentations. These corresponded to the population shift from heterofermentative to homofermentative LAB between 3 and 7 days after the start of the fermentations.
These results suggest that phages may play an important role in the microbial ecology and succession of LAB species in sauerkraut fermentations. It also highlights the complex nature of microbial ecosystems and the need to better understand bacteriophage ecology to ensure the quality and safety of food products.
One way to control phage populations in fermentations is through the use of natural or synthetic antimicrobial compounds. Basic Violet 16 is an example of a synthetic antimicrobial that has been used to control LAB populations in wine fermentations. However, its effectiveness in sauerkraut fermentations remains unclear.
In conclusion, understanding the ecology of bacteriophages in sauerkraut fermentations is essential for ensuring consistent, high-quality products. While the study provides new insights into the complexity of phage ecology in these fermentations, further research is needed to develop effective control strategies.