Development and optimization of a loop-mediated isothermal amplification (LAMP) assay for the species-specific detection of Penicillium expansum

Penicillium expansum is the main cause of Blue Mold Decay, which is the economically most significant post-harvest disease on fruits. It occurs especially on pomaceous fruits such as apples and pears but also on a wide range of other fruits such as grapes or strawberries. Besides its negative economic effects on the industry, the fungus is also of health concern as it produces patulin, a mycotoxin known to provoke harmful effects in humans. A specific and rapid detection of this fungus therefore is required. In the current study, a loop-mediated isothermal amplification (LAMP) assay was developed and optimized for the species-specific detection of P. expansum. The assay showed high specificity during tests with genomic DNA of 187 fungal strains. The detection limit of the developed assay was 25 pg genomic DNA of P. expansum per reaction. The assay was successfully applied for the detection of the fungus on artificially contaminated apples, grapes, apple juice, apple puree, and grape juice. The developed assay is a promising tool for rapid, sensitive, specific, and cost-efficient detection of P. expansum in quality control applications in the food and beverage industry.

Automated summary

Penicillium expansum, the main cause of Blue Mold Decay, is economically significant and poses health concerns due to the production of patulin. A LAMP assay was developed for specific detection, showing high specificity and sensitivity for P. expansum on various fruits. This assay serves as a promising tool for rapid and cost-efficient detection of the fungus in quality control applications in the food and beverage industry.