Mycobiota of the Production Environment of Dairy Processing Enterprises: Comparative Analysis of Structure and Prevalence

Introduction.  Microbial contamination by mold fungi remains a serious problem for the dairy industry. Traditional disinfectants are often ineffective against resistant forms, which necessitates the development of new control approaches based on understanding the structure of the resident mycobiota of specific production facilities.

Objective — a comparative analysis of the composition, frequency of occurrence, and spatial distribution of mycobiota in the air and on equipment surfaces at three dairy processing plants.

Materials and Methods. The study was conducted at three enterprises. Air sampling (200 L) was carried out using the aspiration method with deposition on Sabouraud agar. Surface swabs were taken from an area of 100 cm². Species identification of fungi and yeasts was performed using MALDI-TOF mass spectrometry.

Results. It was established that the core of the resident mycobiota in all environments is formed by three species: Penicillium gladioli (21.3% in air and 33.3% in swabs), Penicillium polonicum (18.0% and 16.7%), and Cladosporium pseudocladosporioides (16.4% and 22.2%). P. polonicum was detected at all enterprises. Concurrently, unique profiles reflecting the specifics of each production were identified: at the cheese factory, Geotrichum candidum and the soil pathogen Thanatephorus cucumeris were identified; at the plant with a wide product range, maximum diversity of Penicillium species was recorded, along with the presence of Aspergillus wentii and Botrytis cinerea. Hidden contamination foci were discovered: Penicillium chrysogenum and P. rubens were detected only in swabs despite negative air analysis results. A significant proportion (11.5%) consisted of microorganisms not identified by the standard MALDI-TOF database.

Conclusions. The microbial ecosystem of the production environment represents a complex consisting of a universal core of highly adapted contaminants and a unique set of species determined by technological processes. The obtained data demonstrate the necessity of transitioning from universal protocols to the development of personalized microbiological control programs based on the analysis of the resident mycobiota of a specific enterprise.

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