SCIENCE LAB SCOOPS : COLOR INTERNS RESEARCH [ 2 ]

Researchers solve the mystery of a green cheese that turned white : The lab of Benjamin Wolfe, a scientist at Tufts University in Massachusetts, studies cheese from Jasper Hill Farm in Greensboro, Vt., along with other aged and fermented foods.

His former adviser, Rachel Dutton, had been in Greensboro years-earlier when she met Charlie Kalish, a farm intern at the time. In 2006, Mr. Kalish proposed to Dr. Dutton at the cheese cave at the farm. [ She said yes. ]

The cheese wheels in the cave that day had their usual distinctive rinds; a '' very avocado-limey green color,'' Dr. Wolfe said. But not long after they began to fade.

The color change might have meant that a new microbe was dominating the cheese and ecosystem. Researchers hinted at a different explanation. 

The scientists knew the green color came from a mold called Penicillium solitum.

In the lab they'd noticed that mold grown from the farm sometimes spontaneously switched from green to white. The reason was a mutation in a gene that makes melanin.

By collecting new samples in 2022 and comparing their genetics with those of the 2016 samples, the researchers found that mutant P. solitum strains had taken over.

And the mutants did not have the ability to make melanin.

The World Students Society thanks Elizabeth Preston.