Abstract: As living standards improved, consumers are much more concerned about the quality of dairy products. Microorganism contamination of dairy products has been a key factor in intense market competition. When lac vaccinum is in reserve, most psychrophilic bacteria, mainly Pseudomonas and Xanthomonas, produce proteinase and lipase which tolerate pasteurization even UHT curing, reducing protein and grease. Cleavage products will change special flavor, deteriorate quality, shorten deadline, heavily influence the quality of dairy products, which will damage the products image and consumer health. The species, quantity and distribution of psychrophilic bacteria are different in each area, and the difference lies in environment, equipment and staff. The control and detection of lac vaccinum in early stage is pivotal to reduce the hazard of psychrophilic bacteria. The text discusses the isolation and decontamination, physiological reaction and PCR detection of psychrophilic bacteria,and then according to the bacteria specificity gene sequence, we designed PCR primer,collected genome DNA for PCR rapid test, tested and contrasted sequence,then confirmed the bacterium.
Keywords: Milk; Psychrophile;Isolating; Microbiological characteristics; PCR
