Classification of Species in the GenusPenicilliumby Curie Point Pyrolysis/Mass Spectrometry Followed by Multivariate Analysis and Artificial Neural Networks
✍ Scribed by Nilsson, Torben; Bassani, Maria R.; Larsen, Thomas O.; Montanarella, Luca
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 592 KB
- Volume
- 31
- Category
- Article
- ISSN
- 1076-5174
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✦ Synopsis
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 Penicilliurn italicurn, P. expunsum and P. digituturn 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 cheeseassociated fungi Aspergillus versicolor, P. discolor, P. roqueforti, P. soliturn, P. verrucosum, P. commune and P. palituns. However, some dificulties appeared in distinguishing the closely related species P. commune and P. palituns. 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.