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Oct. 15 (UPI) -- Scientists have finally unraveled the roots of Camembert's funky fungal flavors.
In the lab, researchers watched as wild blue fungal strains evolved, in just a matter of weeks, into tamer, more appetizing strains resembling their domesticated cousin, Penicillium camemberti.
Their observations offered scientists new insight into the nature of fungal domestication. Under the right conditions, wild strains can be quickly transformed into edible fungi.
For some time, Benjamin Wolfe, a microbiologist at Tufts University, had been growing and analyzing Penicillium commune, a wild fungal strain that causes cheese and other foods to spoil. It's blue in color and smells like a wet basement. But in the lab, scientists watched as the fungus quickly evolved.
"Over a very short time, that funky, blue, musty-smelling fungus stopped making toxins," Wolfe said. "That suggested it could really change quickly in some environments."
Inspired by what they witnessed, Wolfe and his lab partners set out to collect wild strains of Penicillium molds from the walls of a cheese cave in Vermont. Back in the lab, scientists grew the collected strains in dishes containing cheese curds. In some dishes, the wild strains were grown solo, while in others, scientists placed additional fungi -- strains known for their ability to colonize cheese.
After a week, all of the strains were blue-green and fuzzy. They were relatively unchanged. But after three or four weeks, and relocation to a new dish of cheese curds, scientists began to notice a transformation. In more than a third of the test dishes, the wild strains started to look and smell more like P. camemberti. Some strains appeared whiter and smoother, others less fuzzy.
Genomic analysis showed that not much had changed genetically. Instead, the environment triggered the fungal strains to alter the expression of their genes.
"It's not necessarily just genetic," Wolfe said. "There's something about growing in this cheese environment that likely flips an epigenetic switch. We don't know what triggers it, and we don't know how stable it is."
The latest research, published this week in the journal mBio, suggests the fungal strains associated with fermented foods, including cheese, beer and wine, were likely accidentally domesticated thousands of years ago. Their lab tests also suggest new cheese flavors could be created by controlling the domestication of wild strains.
"The fungi that are used to make American camembert are French," said Wolfe, "but maybe we can go out and find wild strains, bring them into the lab, and domesticate them. We could have a diverse new approach to making cheese in the United States."