Detection of yeast by PCR in sucrose solutions using a sample preparation method based on filtration

An assay based on PCR was developed for the detection of yeast in naturally contaminated industrial sugar solutions. A number of characterized as well as non-characterized yeast strains, isolated from samples from a sugar ref inery, were detected with the PCR assay. Specificity tests showed that the presence of neither bacteria nor mould resulted in false positive results. A concentration step, based on filtration, was employed prior to the PCR de tection in order to reach a detection level of 0.1 c.f.u./ml of naturally c ontaminated sugar solution. The detection method based on PCR was found to be more rapid (< 5 h) and easier to perform than the slower and more labour -intensive, traditional culturing techniques.