Technique standardization to characterize at the molecular level native yeasts of Paipa cheese produced in Colombia

Abstract

Paipa cheese is the only traditional produced cheese in Colombia that involves a process of maturation. The presence of yeast is important because some of them help metabolize lactate and promote deacidification, but others can cause changes on the aroma and flavor. For this reason, a molecular identification is critical. We used 17 samples of strains isolated from different stages of production and maturation. DNA extraction was performed by adapting the DNeasy Plant Kit (QIAGEN). PCR amplification of the segments of the 26S ribosomal DNA region was done, specifically the D1/D2 domain of the yeast isolates, with the primers NL1 and NL4 in varying conditions of volumes, time and temperature they were checked by agarose gel electrophoresis.The values of ​​ DNA ranged between 14.0 and 21.6 ng/uL. Amplification of a fragment between 600 and 700 bp was achieved independently of the conditions, confirming the purity of extracted DNA and standardization of protocols used, which will lead to the final molecular characterization.