Detection and vitality of Lactococcus lactis in cheese ripening

Recent evidences highlighted the presence of Lactococcus lactis during late cheese ripening. Thus, the vitality of this microorganism, well known as dairy starter, has been evaluated, in this research, throughout cheese manufacturing and ripening. Quantitative PCR (qPCR) and Reverse Transcriptase (RT)-qPCR protocols, for the detection and quantification of L. lactis in cheese, were developed. Both commercial and laboratory miniature cheeses were analyzed by culture-dependent and -independent methods to monitor the vitality of the microorganism. RT-qPCR highlighted the presence of metabolically active populations of L. lactis in most of the cheeses analysed at advanced stages of ripening.