Joint research conducted by cultures company Danisco and one of Canada’s research institutions, Universite Laval, has shed light on the mechanisms behind the natural bacterial immune system CRISPR/Cas. The findings, published today in the scientific journal Nature, highlight the system’s potential as a simple, natural way to generate more robust organisms with built-in resistance to virus attack.
The research into CRISPR – clustered regularly interspaced short palindromic repeats – and CRISPR-associated genes (Cags) looked at the defence mechanisms in Streptococcus thermophilus – a bacterium widely used in yogurt cultures. “We found that the CRISPR/Cas system is responsible for cleaving bacteriophage and plasmid DNA. It is this cleavage activity that gives certain strains their bacteriophage immunity,” says Rodolphe Barrangou, senior scientist at Danisco.
Based on these results, it is believed CRISPR/Cas can be used to generate bacteria that neither acquire nor spread antibiotic-resistance genes. “This is a great new episode in the Danisco CRISPR story, giving us additional knowledge of value towards the development of safer, more robust bacteria strains,” says Barrangou.
For the food industry, the immune system represents opportunities to develop bacteriophage-resistant cultures – a powerful new tool in, for example, yogurt and cheese manufacture where bacteriophages are the number one threat to successful processing. New strategies to combat the spread of antibiotic-resistant bacteria are among the many other application possibilities.