Classification of species in the genus Penicillium by Curie point pyrolysis/mass spectrometry followed by multivariate analysis and artificial neural networks.

Torben Nilsson, Maria R. Bassani, Thomas Ostenfeld Larsen, Luca Montanarella

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    Curie point pyrolysis/mass spectrometry of Penicillium species was performed with 530 degrees C Curie point foils. The mass spectra were submitted to principal component analysis, canonical variates analysis and hierarchical cluster analysis, producing a final dendrogram by the use of average linkage clustering. By this approach a successful classification of the species Penicillium italicum, P. expansum and P. digitatum originating from fruits was obtained. Isolates of the same species grouped together in the dendrogram, while the different species were distinguished. Also when grown on two different agar media, replicates of the same species grouped together. Likewise, a satisfactory classification was achieved by multivariate analysis of the data for various isolates of the cheese-associated fungi Aspergillus versicolor, P. discolor, P. roqueforti, P. solitum, P. verrucosum, P. commune and P. palitans. However, some difficulties appeared in distinguishing the closely related species P. commune and P. palitans. Such difficulties became greater on including more isolates and limiting the analysis to five of the species. The use of back-propagation artificial neural networks, in contrast, resulted in a correct classification in all cases. Thus, it is concluded that Curie point pyrolysis/mass spectrometry is useful in chemotaxonomic studies of the closely related species in the genus Penicillium.
    Original languageEnglish
    JournalJournal of Mass Spectrometry
    Volume31
    Issue number12
    Pages (from-to)1422-1428
    ISSN1076-5174
    DOIs
    Publication statusPublished - Dec 1996

    Keywords

    • artificial neural networks
    • cluster analysis
    • Curie point pyrolysis mass spectrometry
    • multivariate analysis
    • Penicillium

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