Abstract: Psychrotrophs and thermoduric bacteria are the major contaminating microorganisms in dairy products, which affect the quality and safety of dairy products. Therefore, it is particularly important to study the relationship among contaminating microbial communities, trace the pathways and sources of contamination, and reduce the hazards of contamination. Typing and identification technologies provide strong support for the precise identification and classification of contaminating microorganisms. This paper focuses on recent progress in the development of typing and identification methods for psychrotroph and thermoduric bacteria in dairy products from three aspects: phenotyping, molecular biology typing, and mass spectrometry typing. The principle, application, advantages and disadvantages of each technology are outlined, and the problems with the existing typing and identification methods are discussed. Finally, this review concludes with an outlook on future development directions. It aims at providing a scientific basis for the selection of suitable methods for the typing and identification of psychrotrophs and thermoduric bacteria in dairy products for more accurate and efficient identification and control of contaminating microorganisms in dairy products, thereby guaranteeing their quality and safety.

Key words: psychrotrophs, thermoduric bacteria, identification, typing, dairy products, quality and safety