General food mycology based on gene-probes and development of new isolation methods

In this project the focus has been on the use of RAPD for identifying ramets or clones of fungi to see if the same clones of a particular species invade different foods or factories (identification of contamination sources). The RAPD method has been optimized for use with fungi from cheeses, especially Penicillium caseifulvum and P. commune. The method could differentiate clones from different dairies and was found to be very robust, at least when using the same PCR-machine. Concerning differentiation at the species level parts of two genes, the ITS regions of ribosomal DNA and wetA genes from several food-borne penicillia have been sequenced. Penicillium roqueforti, P. carneum,P. paneum, and P. expansum had differences enough in the ITS region so specific probes could be suggested for analysis of foods, whereas other species were too alike in the ITS sequence to be of use for specific detection. The hope is that the wetA gene or other genes are of use for specific probes for all important food-borne species.