Detection, Identification, and Diffusion of Yeasts Responsible for Structural Defects in Provolone Valpadana PDO...

Area of Science:

• Food microbiology
• Dairy science
• Molecular biology

Background:

• Structural defects in Provolone Valpadana Protected Designation of Origin (PDO) cheese pose a significant challenge to product quality.
• Identifying the specific microbial agents responsible is crucial for implementing effective control measures.

Purpose of the Study:

• To identify the microbial culprits behind structural defects in Provolone Valpadana PDO cheese.
• To determine the prevalence and distribution of these microbes throughout the cheese production process.

Main Methods:

• Microbiological analysis of defective cheeses and processing intermediates.
• Identification of yeast isolates using D1/D2 region sequencing of the 26S rRNA gene.
• Yeast and bacterial metabarcoding and Random Amplified Polymorphic DNA-PCR (RAPD-PCR) analysis.

Main Results:

• Yeasts were consistently identified as the dominant microbial group in defective cheeses.
• Key yeast species identified include Saccharomyces cerevisiae, Kluyveromyces marxianus, and Debaryomyces hansenii.
• RAPD-PCR suggested yeast biofilm formation in the dairy environment, with specific genotypes recurring across samples.

Conclusions:

• Yeasts are the primary agents responsible for structural defects in Provolone Valpadana PDO cheese.
• The presence of specific yeast genotypes along the production line indicates a potential for persistent contamination and biofilm development.
• Further investigation into biofilm control strategies is warranted to ensure cheese quality.