LAUSR

Abstract Kazachstania servazzii and Candia sake are involved in kimchi fermentation and form undesirable white colonies on the kimchi surface in the late stage of fermentation. To quantify the presence of these two yeast species, we developed real-time PCR assays based on a TaqMan probe, targeting the internal transcribed spacer region. The K. servazzii- and C. sake-specific real-time PCR amplified the target yeast species only, without any cross reactivity with non-target yeast species. The limit of detection of each assay was 1.2 × 102 and 3.1 × 102 CFU/mL for K. servazzii and C. sake, respectively. The quantitative real-time PCR assays were validated through quantitative analysis of yeast content inoculated into kimchi. In addition, these methods were applied to analyze the change in yeast content during kimchi fermentation. During a 50-day period of fermentation, K. servazzii increased to 1.9 × 106 CFU/g, whereas C. sake was below the detection limit (