Deconstructing a Deadly Mold, Gene by Gene
By Erin
Peabody October 16, 2006
Fungi: Can't live with them, can't live without them.
While many of these tiny spore-producers are lauded for their
industriousness (think penicillin, yeast for leavened bread, and mold-enhanced
delicacies like Roquefort and blue cheeses), it seems there are just as many
noxious fungi out there ready to contaminate food, houseseven the air we
breathe.
And no mold is as dark a character as Aspergillus flavus, which
is why scientists with the Agricultural Research Service (ARS) and their collaborators are
scrutinizing this fungus, one gene at a time.
A. flavus can be terribly destructive. With an affinity for
corn, peanuts, cottonseed and tree nuts such as almonds and walnuts, it can
plague vast acreages of crops in the United States and threaten food and animal
feed security worldwide.
What's so dangerous about A. flavus are its deadly toxins,
known collectively as aflatoxin. These fungal poisons are the second leading
cause of aspergillosis in humans. Considered to be among the most potent
carcinogens in nature, they've also been linked to some forms of cancer.
Because of the risks associated with aflatoxin, the
Food and Drug Administration has put
safeguards in place to protect consumers. But federal researcherslike ARS
geneticist
Jiujiang
Yuwould like to find ways to keep toxic fungi from occurring in the
first place.
Yu, who works at the ARS
Southern
Regional Research Center in New Orleans, La., was part of a team of
scientists who recently sequenced a strain of the A. flavus fungus.
Along with ARS researchers
Ed
Cleveland and
Deepak
Bhatnagar, Yu collaborated on the project with
North Carolina State University's Gary Payne
and William Nierman of The Institute for Genomic
Research in Rockville, Md.
One of the team's primary goals is to pinpoint which of the fungus'
13,000 genes regulate toxin production. They'd like to disable them so they can
rob the fungus of its poison-making machinery.
Read more
about this and other food safety research in the October 2006 issue of
Agricultural Research magazine.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.