Purpose: To evaluate seasonal influence on microbial diversity and dynamic during elaboration and ripening of traditional Chihuahua cheese.
Methods: Five cheese factories (A-D) were visited three times during a year in different seasons and portions of raw milk, curd (after cutting), cheddaring (before salting) and freshly prepare cheese were obtained; also, portions of cheese ripened in the laboratory (30-270 d) were taken and conserved at -20°C until analysis. From a total of 144 samples, genomic DNA was extracted and the V3 region of the16S rRNA gene was amplified; amplicons were separated using denaturing gradient gel electrophoresis (DGGE) by a linear denaturing gradient of 30-70% of urea and formamide.
Results: The banding pattern of manufacturing samples exhibited between 4 and 18 different bands, noticing more microbial diversity on farm A (18 bands); ripening cheese samples showed 5 to 13 different bands, being cheeses form factory E the highest (13 bands). Some bands prevailed during all the period of study, other appeared during ripening, and a few disappeared or the band was less intense throughout the manufacturing and ripening processes. Other bands could only be observed in a dairy or in a season in particular, which is a clear indication of the effect of season and the particular manufacturing practices and conditions of each dairy on the dynamic and diversity of microorganisms.
Significance: It was possible to describe the dynamics and diversity of microorganisms involved on the manufacturing and ripening of a traditional cheese made from raw milk, using DGGE as analytical tool. Seasonal and location variations were observed.