Cheese genes can be easily swapped, French scientists say

Genes can be transferred from one species of cheese Penicillium fungi to another, according to French researchers.

The study, Adaptive Horizontal Gene Transfers between Multiple Cheese-Associated Fungi, was published in Cell Press journal Current Biology.

These findings, it said, may lead to improvements in cheese making.

In contrast, it should also cause cheese producers to be more cautious, as researchers said the easy ability to swap may cause food safety concerns as well.

One finding that may help cheese manufacturers is how to obtain faster growing strains, but this also may lead to different fungal species in the same cheese, something that could be damaging.

Transferring genes to different varieties of cheese may produce toxins, for example, something that could damage the cheese.

‘A competitive advantage’

Antoine Branca, a senior researcher on the study and lecturer at L'Université Paris-Sud and CNRS, told DairyReporter the researchers wanted to look at domestication of cheese, as this can be looked at to view how selection of individual traits can affect a cheese.

Branca said the research team wanted to look at varieties of cheese that have been domesticated for cheese production, such as P. roqueforti for blue cheeses like Roquefort and P. camemberti for soft cheeses like Camembert.

The scientists compared 10 different Penicillium species and found horizontal transfers carrying “crucial metabolic genes” were important to the adaptation of cheese.

Two of these regions were found to be nearly identical, indicating that the evolution has been selective.

These traits are associated with faster growth and improved competitiveness of the strain, researchers said.

“It’s kind of unexpected,” he said. “It means that the sequence we found that were close between those two were probably recently transferred … When we look at some function of the genes, the function transferred between the two. They were, for instance, genes involved in metabolism of lactose.”

“We tried to see if the strains used for cheese industry had some kind of advance versus the cheeses that are not, and yes; they do have an advantage, probably because of that transfer … There’s a competitive advantage.”

Looking for a greater variety

What the researchers learned, Branca said, is that there is more diversity than they previously thought, especially among the blue cheeses utilized by cheese producers.

“Some don’t have the ability to transfer genes or to grow better, so there is diversity there and don’t know yet what they provide,” he said. 

“Much of it is not just about growing well but there are other things that maybe cheesemakers have to be aware. Maybe we need to make better strains in the future, so now we find [what advantages] these strains have.”

From what the researchers know now, he said they can make better predictions for how to improve these fungi strains and give them different features.

“Over the past 100 years, there were clearly some strain improvements in the cheese industry,” he said. “It’s kind of helping to see that now we know what you are really doing to improve your strains. You can use this to improve strains even more.”

Source Current Biology http://dx.doi.org/10.1016/j.cub.2015.08.025

Adaptive Horizontal Gene Transfers between Multiple Cheese-Associated Fungi,

Authors: J. Ropars, R. Rodríguez de la Vega, M. López-Villavicencio, J. Gouzy, E. Sallet, É.eDumas, S. Lacoste, R. Debuchy, J. Dupont, A. Branca, T. Giraud