Scientists found that bacterial blotch in white button mushrooms is caused by multiple bacteria, a discovery that could improve disease detection and lead to more sustainable treatments for growers.
A University of Florida study has uncovered an important new clue about a disease that has affected white button mushrooms for more than 100 years. The popular mushroom is widely valued for its nutritional benefits and versatility in everyday meals.
As a major specialty crop, white button mushrooms are often cited as an example of the “food is medicine” concept because they can help support healthy diets when included in common foods such as salads, appetizers, and other dishes.
But growers continue to face problems from bacterial blotch, a disease that lowers yields, shortens shelf life, and reduces the market value of mushrooms by causing brown or yellow discoloration. In some cases, symptoms do not appear until mushrooms are already in stores or in consumers’ homes.
Multiple Bacteria Linked to Bacterial Blotch
Researchers from the UF Institute of Food and Agricultural Sciences (UF/IFAS) found that bacterial blotch is not caused by a single pathogen, as previously believed. Instead, the disease is linked to a complex mix of harmful bacterial species that thrive in the warm, humid indoor conditions used for mushroom production.
“For years, the industry has struggled with treatments that provide inconsistent results against bacterial blotch,” said Samuel Martins, co-author and assistant professor in the UF/IFAS Department of Plant Pathology. “As part of a separate $7 million U.S. Department of Agriculture grant involving Penn State, the University of Delaware, and UF/IFAS, we are developing advanced diagnostics and sustainable solutions to strengthen mushroom farms nationwide.”
To conduct the study, the UF/IFAS team used DNA sequencing, chemical profiling, and traditional laboratory testing to analyze mushrooms infected with bacterial blotch. Samples were collected from several mushroom production sites across the southern United States. The researchers found that the involvement of multiple bacterial species makes the disease more difficult to detect, predict, and control using standard treatment methods.
Researchers Identify 17 Pathogenic Species
“We found more than 17 different species of pathogenic bacteria associated with the disease,” said Sameerika Mudiyanselage, the study’s lead author and a doctoral student of Martins and Romina Gazis at the UF/IFAS Tropical Research and Education Center. “While two well-known bacterial pathogens dominated the known disease profile, we also detected a surprisingly high level of another group of bacteria that has not previously been linked to the mushroom disease.”
The discovery suggests there are additional contributors to bacterial blotch that had previously gone unrecognized. Researchers say this may help explain why the disease has remained a costly and persistent problem despite ongoing treatment efforts.
“We hope that expanding our research will lead to the development of better diagnostics and more effective treatments to address the full group of disease-causing bacteria in white button mushrooms,” she said.
Sustainable Treatments and Eco-Friendly Solutions
In addition to identifying the bacteria involved, the researchers are also exploring more sustainable ways to manage the disease. Current follow-up studies are examining plant-based essential oils, beneficial microbes, and other biological products as possible alternatives to conventional chemical treatments.
“Ultimately, our goal is to provide growers with practical, science-based solutions that help strengthen mushroom farming systems,” said Martins. “By understanding the complexity of bacterial blotch and the role of microbial communities, we can develop better eco-friendly management practices that reduce losses while improving sustainability.”
New Findings Could Transform Mushroom Disease Management
UF researchers found that bacterial blotch in white button mushrooms is caused by multiple bacterial species rather than a single pathogen.
The disease creates major challenges for mushroom growers by reducing crop yields, shortening shelf life, and causing visible blemishes that make mushrooms difficult to sell.
The findings could improve disease detection and support the development of more effective and sustainable treatments for mushroom farms across the United States.
Reference: “Genomic insights into a multispecies bacterial pathogen complex driving bacterial blotch in white button mushrooms” by Sameerika D. Mudiyanselage, Michelle Lee, Jose C. Huguet-Tapia, Romina Gazis and Samuel J. Martins, 23 April 2026, Microbiological Research.
DOI: 10.1016/j.micres.2026.128532
Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.