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Classification of Species in the Genus Penicillium by Curie Point Pyrolysis/Mass Spectrometry Followed by Multivariate Analysis and Artificial Neural Networks
Author(s) -
Nilsson Torben,
Bassani Maria R.,
Larsen Thomas O.,
Montanarella Luca
Publication year - 1996
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/(sici)1096-9888(199612)31:12<1422::aid-jms442>3.0.co;2-5
Subject(s) - dendrogram , canonical analysis , chemistry , mass spectrometry , principal component analysis , curie temperature , botany , biology , chromatography , statistics , mathematics , physics , population , demography , quantum mechanics , ferromagnetism , sociology , genetic diversity
Curie point pyrolysis/mass spectrometry of Penicillium species was performed with 530°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 .