Surface mycobiota of home-made dry cured sausages from the main producing regions of Argentina and morphological and biochemical characterization of Penicillium nalgiovense populations

Abstract

The characteristics and quality of home-made dry cured sausages can be recognized and associated with the region of origin. The characteristics of this type of sausages result from the superficial mycobiota that spontaneously colonizes the products. The aim of this study was to identify the house mycobiota associated with home-made dry cured sausages from different localities of Argentina and characterize the populations of Penicillium nalgiovense present by morphological and biochemical markers. To this end, 79 samples were collected from 10 localities of three main producing regions (Buenos Aires, Córdoba and La Pampa provinces). A total of 196 isolates belonging to six genera and 17 species were obtained. The predominant genus was Penicillium (134 of the isolates) and the predominant species was P. nalgiovense (108 isolates). The isoenzyme patterns of α-esterase (α-EST; EC 3.1.1.1) and Malate dehydrogenase NADP+(MDHP; EC 1.1.1.40) were characterized in 48 of these isolates (ten from Colonia Caroya, ten from Oncativo, ten from Tandil, nine from Mercedes and nine from La Pampa). A total of 26 bands were observed: 17 for α-EST and 9 for MDHP. α-EST was the most polymorphic isoenzyme, whereas MDPH presented no polymorphism. The results were subjected to numerical analysis. Cluster analysis revealed the formation of two groups: Group I formed by 24 isolates from Córdoba and Buenos Aires provinces and Group II with 24 isolates from La Pampa and Buenos Aires province. These data suggest the existence of morphological and biochemical variations among P. nalgiovense populations with different geographical origin.