Foods contaminated with fungal toxins can be a problem at best, and potentially dangerous at worst. But new research shows that removing just one protein can leave some fungal toxins high and dry, and that’s potentially good news for food safety.
Mycotoxins, which are harmful chemicals produced by fungi, can spoil food like grains and make us sick. Aflatoxins, which is one of the most dangerous forms of mycotoxins can cause liver cancer, and other health problems for people.
“It is a silent enemy,” says fungal researcher Özgür Bayram of Maynooth University in Ireland, because most people don’t notice when food like corn or wheat is spoiled.
For years, researchers have known that some fungi produce these toxins, but didn’t know all the details. Bayram and his colleagues have now identified a number of proteins Mycotoxins are responsible for the increase in mycotoxins production. Genetically engineering fungus Aspergillus nidulansResearchers report that removing even one protein from the body can prevent toxins from being created. Nucleic Acids Research.
“There is a long string of genes that is involved with the production of proteins that, in a cascading effect, will result in the production of different mycotoxins,” says Felicia Wu, a food safety expert at Michigan State University in East Lansing who was not involved in the research.
Bayram says that the new proteins function as a key for starting a car. The researchers were interested in removing the key and preventing the start signal from getting through.
Bayram and his group identified the proteins in A. nidulansThe key is made up of four proteins. Researchers genetically engineered the yeast to remove each protein individually. The team discovered that if any of the four proteins is missing, the key will not activate mycotoxin ignition.
Another study, which has not been published yet, showed that the same group proteins were deactivated in a closely related fungus. A. flavusBayram said that aflatoxins can be made by fungi, but they prevent their production. “So this is a big success because we see, at least in two fungi, the same [protein] complex does the same job.”
The new work “is building upon a body of research that’s been done over decades” to prevent fungal contamination of food, Wu says. This type of contamination can be controlled using a variety of methods. This is because not all of these methods are effective. A. flavusWu explained that aflatoxins are produced by some strains. Wu suggests that you sprinkle nontoxic strains onto peanuts or corn fields to avoid contamination. These fungi can multiply, which can prevent other toxic strains from taking root.
This is just one method that researchers use. These toxins can be eliminated by genetic engineering (SN: 3/10/17). Future applications of the research could include genetically tweaking a toxin making fungus to be used on crops and other places. “We can basically prevent aflatoxin contamination in food, for example, in the field, even in the warehouses, where a lot of contamination takes place,” Bayram says.
Water molds, which are fungi and fungi-like organisms, can cause significant damage. a third of the world’s food crops each year. Bayram claims that if contamination could be avoided, food saved would feed 800 million people by 2022.
The new research is a good start, Wu says, but it will still be a “challenge to try to understand how this can be operationalized for agricultural purposes.” It’s unclear how scalable the technique is, she says, and getting U.S. regulatory agencies to approve the use of a genetically modified fungus on key food crops might be difficult.
