Use of Microstation~(TM) (Biolog): creation and application of a database to differentiate Penicillium verrucosum from Penicillium nordicum

摘要

To avoid the presence of ochratoxin A (OTA) in dry-cured meat products, which are naturally exposed to surface fungi development, it is important to identify the fungal species which can develop on such products and, in particular, those which can produce OTA. Amongst the latter, the most common are Penicillium verrucosum, Penicillium nordicum and Aspergillus ochraceus; however, only P. nordicum and A. ochraceus are deemed responsible for OTA production in protein substrates. In particular, P. nordicum has been recognised as a new and different species from P. verrucosum only in recent years, since these two species cannot be distinguished morphologically ( 1 ) and can be differentiated only by using specific cultural (2,3) and molecular (4-7) techniques. These techniques have also enabled us to identify the origin of isolates: the supply chain of grains for P. verrucosum and of dry-cured meat products for P. nordicum (8, 9). However, the three methods used - morphological, cultural and molecular-are not deemed exhaustive if applied individually, but only if applied in combination.