The surface microflora dynamics of bacterial smear-ripened Tilsit cheese determined by T-RFLP DNA population fingerprint analysis

Three Tilsit-type smear-ripened cheeses were manufactured: one was treated with an undefined smear starter mix, the other two were treated with a different defined smear starter mix. The composition of the surface microflora over 8 weeks of ripening was analyzed using Terminal Restriction Fragment Length Polymorphism (T-RFLP) analysis. During the whole period of ripening starter strains were found to be present; additionally, strains apparently acquired from the environment were found. Most of the strains reached a maximum level after 2-4 weeks but were not observed after 8 weeks, except for the Corynebacterium species, which remained as the dominant bacterial genus on the surface of the fully ripened cheese. This study constitutes the first and successful application of an ALFexpress™ automatic sequence analyzer to T-RFLP analysis. It was found to be an excellent tool for rapid and specific culture-independent assessment of population composition and dynamics of a cheese system.