'Genetic Literacy Project' Details John Gibbons's Research into the Domestication of Fungi
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About 9,000 years ago in China, as humans were beginning to domesticate corn and pigs, we also learned to tame fungi—including Aspergillus oryzae, a mold that would become essential to traditional Asian foods such as soy sauce and sake. This fungus kickstarts fermentation by breaking down starches and proteins, paving the way for other microbes to complete the process.
The fungus's wild relatives, however, are highly toxic and destructive, capable of producing carcinogens and devastating crops like corn and peanuts. Scientists are now uncovering how A. oryzae evolved from a harmful mold into a safe, domesticated organism, offering insights into the still-mysterious process of microbial domestication. John Gibbons, microbial genomicist and associate professor in the College of Natural Sciences's Department of Food Science, is one of these scientists.
A recent Genetic Literacy Project article outlines the recent discoveries made by Gibbons and others that have revealed the history of A. oryzae.
In one study, "scientists compared the genome of A. oryzae 14160, an industrial strain from China, with the genome of A. oryzae RIB40, a strain that was sequenced in 2005. In a report published in Frontiers in Microbiology in 2021, the team found that more than half of the aflatoxin gene cluster was deleted in strain 14160, while strain RIB40 has mutations in key genes here and there."
Gibbons argues that from strain to strain, "there’s one deletion in the aflatoxin gene cluster that consistently appears," as illustrated in an analysis he led with then-graduate student Katherine Chacón-Vargas in 2021, after analyzing hundreds of strains of the molds.
"This finding suggests that at some point, a strain of wild A. flavus mold acquired the deletion, which rendered it harmless. After that, other genetic changes—mutations, deletions, other alterations—freely accumulated in the aflatoxin genes since they were no longer being used."
— Genetic Literacy Project
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