Identification of Food Spoilage Fungi Using MALDI-TOF MS: Spectral Database Development and Application to Species

Nolwenn Rolland1,2, Victoria Girard1, Valérie Monnin1

  • 1bioMérieux, R&D Microbiologie, Route de Port Michaud, F-38390 La Balme les Grottes, France.

Insights

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) enhances fungal identification in food safety. Expanding the VITEK® MS database improves accuracy, particularly for differentiating closely related species.

Area of Science:

  • Food microbiology
  • Analytical chemistry
  • Mycology

Background:

  • Fungi cause significant food loss and produce mycotoxins.
  • Accurate fungal identification is crucial for food safety and quality.
  • MALDI-TOF MS offers rapid and reliable fungal identification.

Purpose of the Study:

  • Expand the VITEK® MS database with food-relevant fungal species.
  • Evaluate the performance of the expanded database for fungal identification.
  • Assess the ability of MALDI-TOF MS to differentiate species within complexes.

Main Methods:

  • Added 380 yeast and mold strains (51 genera, 133 species) to the VITEK® MS database.
  • Included species from five major fungal complexes (e.g., Aspergillus, Fusarium, Colletotrichum).
  • Validated database performance using cross-validation and external testing with 78 isolates.

Main Results:

  • Achieved 96.55% correct identification via cross-validation.
  • Reached 90.48% correct identification in external validation.
  • Demonstrated MALDI-TOF MS capability in differentiating closely related fungal species.

Conclusions:

  • The expanded VITEK® MS database improves fungal identification accuracy.
  • MALDI-TOF MS is effective for routine fungal identification in industrial settings.
  • This technique aids in ensuring food safety and quality by enabling precise fungal detection.