Rapid detection and identification of Lactobacillus spp. in dairy products by using the polymerase chain reaction

Species-specific primers for use in the polymerase chain reaction (PCR) were designed to differentially amplify DNA from the common dairy lactobacillus species Lactobacillus casei , Lactobacillus delbrueckii , Lactobacillus helveticus , and Lactobacillus acidophilus . A method for rapid extraction of bacterial DNA from dairy products was developed. The sensitivity of bacterial DNA extraction from food and subsequent amplification by PCR was 100 cells total. Lactobacillus DNA was extracted and identified from commercial yoghurts, acidophilus milk, and cheeses. The methodology allows the presumptive identification of dairy lactobacilli in less than 6 hours.