Researchers have developed a faster and safer way to edit the genome of Streptococcus thermophilus, the bacterium at the heart of yogurt and cheese production. The advance could speed up innovation in dairy and open new opportunities for microbial research.
S. thermophilus plays a key role in fermentation, shaping flavor, texture, and processing efficiency. Yet modifying its genome has long been difficult. Conventional plasmid-based techniques are slow and complex, while other available methods are often inefficient.
In this study, scientists used the B-6 strain as a model to improve natural transformation — the process where bacteria absorb DNA from their environment. By adding a signaling peptide (ComS17–24), introducing external DNA, and extending incubation time, they raised transformation efficiency from about one in 100,000 cells to one in 100. This was a major breakthrough.
With this improvement, the team created a plasmid-free editing method that is simple, safe, and broadly applicable. They also designed a CRISPR-Cas pathway that relies on the bacterium’s own system, removing the need for additional plasmids. Using these techniques, they produced several modified strains, including ones without CRISPR-Cas systems and another that overproduces the DNA repair protein RecA.
For dairy processors, the benefits are clear. Stronger genetic tools can help create starter cultures that are more reliable, improve fermentation control, and enhance product quality. For researchers, the modified strains provide new models for studying bacterial metabolism and resilience.
By linking natural bacterial processes with modern genome editing, the study delivers a practical step forward. It makes microbial improvement faster, safer, and more accessible — and it positions the dairy sector to benefit from advances once limited to laboratory research.
