Separation of closely related asymmetric Penicillia by pyrolysis-gas chromatography and mycotoxin production

The relationships among nine different isolates of Penicillium crustosum were studied by pyrolysis-gas chromatography (Py-GC) coupled with a pattern recognition analysis (PR). The results obtained were compared to mycotoxin production profiles of the isolates. Based on the Py-GC analyses the isolates could be divided into two well-differentiated groups, and one of these groups could be further subdivided. Based on mycotoxin analyses the isolates could be divided into three groups: one group (P. crustosum sensu stricto) in which the fungi produced penitrem A, roquefortine C, and terrestric acid, one group ("P. caseiphilum" = P. camembertii group II) producing cyclopiazonic acid, and a third group ("P. melanochlorum" = P. mali) with isolates producing none of these toxins. Basically, the Py-GC-PR grouping agreed with the mycotoxin profile grouping, although the agreement was not perfect. The taxonomic treatment of these strains as one species thus seems unsatisfactory. The Py-GC-PR method appears to be quite useful as one aid in establishing criteria for studies of relationships between related fungi.