Characterization of Penicillium roqueforti strains used as cheese starter cultures by RAPD typing

Seventy-six strains of Penicillium roqueforti used as starter cultures for mould ripened blue cheeses have been analysed for their RAPD genotype by us ing three different primers. A comparison of the RAPD patterns within each primer group revealed that the genetic constitution of the strains was simi lar, as most of the strains showed very similar overall patterns. Despite t hese similarities with each primer, distinct RAPD genotype groups could be identified. With one of the primers, it was possible to detect two heteropo lymorphic DNA regions resulting in 13 different groups. With the other two primers, three or four groups could be identified. Between the groups of th e different primers marked correspondence with respect to strain distributi on could be observed, indicating that the polymorphisms detected by the pri mers were not independent. The RAPD patterns were compared to the productio n of secondary metabolites. A correlation was observed between the RAPD pat terns of all primers and the production of mycophenolic acid. In addition, one of the primer (ari 1) was able to distinguish between P. roqueforti str ains producing larger or smaller numbers of metabolites. (C) 2001 Elsevier Science B.V. All rights reserved.