Taqman RT-PCR Analysis for the Identification of the Osmotolerant Yeast Zygosaccharomyces rouxii

Resumo

A rapid method for the identification of the osmotolerant yeast Zygosaccharomyces rouxii was developed based on Taqman RT-PCR. Osmotolerant yeasts cause spoilage of food with a high sugar content (honey, syrups, candies, jams, concentrated fruit juices, etc.). In the course of bioinformatics analysis, a DNA segment containing the 5.8S, 18S and 28S genes of ribosomal RNA and ITS1 and ITS2 intergenic regions specific for Z. rouxii was detected, and primers and Taqman probes were developed. The PCR was optimized both for the concentration of its components and for temperature cycles. It was shown that PCR is specific only for Z. rouxii, and the developed analysis allowed the detection of 10 femtograms of its DNA. The method was validated for the collection microorganisms of different taxonomic groups. As a result of the screening of 22 commercially available sugars and dried fruits, it was established that three types of sugar and six dried fruits were contaminated with these yeasts.