This work studied the qualitative and quantitative proteolytic and lipolytic activities of Yarrowia lipolytica strains isolated from two cheese types. Randomly amplified polymorphic DNA-PCR (RAPD-PCR) analysis was used to compare the cheese strains of Y. lipolytica with strains isolated from other food products and with the type strain of the species in order to investigate the genetic diversity and occurrence of specific environmental groups. Diversity of proteolytic and especially lipolytic activity within Y. lipolytica strains isolated from dairy products was observed. In particular, the degree of specificity for saturated or unsaturated fatty acids as well as for even- or odd-numbered carbon free fatty acids (FFAs) varied among the strains. The RAPD-PCR profiles showed low genetic relatedness between many of the food isolates and the type strain of the species. Such genetic variability needs to be further evaluated. Most of the Y. lipolytica strains appeared to be specific to the particular environment from which they were isolated. However, phenotypic characteristics having technological importance in dairy products and, particularly, lipolytic activities did not correspond to the genetic differences observed by RAPD-PCR analysis.

Water-buffalo Mozzarella (WBM) cheese is one of the several 'pasta filata' or stretched curd cheeses that originated in southern Italy, traditionally manufactured from raw milk employing natural whey starter cultures. Lactose- and galactose-fermenting yeasts isolated from WBM were studied to evaluate their role in the ripening of this cheese. The kinetic parameters of the growth of the yeasts as well as their principal metabolic end-products showed a great variability depending on the species. Moreover, the genetic polymorphism of the yeasts was studied for their differentiation at species level by means of the polymerase chain reaction (PCR) fingerprinting and mitochondrial DNA (mtDNA) restriction analysis. While the differentiation based on metabolic traits was not able to discriminate Kluyveromyces marxianus, Candida kefyr and C. sphaerica, the PCR analysis with primers M13 and RF2 resulted in a reliable and rapid method for differentiating at species level Saccharomyces cerevisiae, K. marxianus, K. lactis and their anamorphic species. Furthermore, mtDNA analysis proved to be more discriminating at strain level.

Enterococci were isolated from semicotto caprino cheese, a traditional cheese produced in Southern Italy: they were a significant part of the microbial population of this cheese, confirming the importance of the presence of these micro-organisms during cheese-making and ripening. They were also identified and studied for their phenotypic and genotypic characteristics: Enterococcus faecalis and Ent. faecium were the most frequently isolated species, followed by Ent. durans, Ent. hirae and Ent. gallinarum. None of the isolates showed lipolytic activity, whereas they were characterized by a relevant proteolytic activity as well as an antagonistic activity towards Listeria innocua. One strain of Ent. gallinarum showed a low-level resistance to vancomycin, while six out of the 79 Ent. faecalis strains possessed beta-haemolysis reaction. The highest acidifying potential in skim milk was obtained by Ent. faecalis isolates. Thirty enterococcal strains representative of the different species at different ripening times were analysed by means of RAPD-PCR, and revealed species-specific profiles for all the considered species.

Artisanal manufactured sausage "salsiccia sotto sugna", produced according to traditional receipts, has been analysed in some areas of Basilicata region. During sausages making and ripening they have been drawn samples. For some products the microbiological analysis showed the potentiality for the selection of lactic acid bacteria and micrococci starters in order to improve the product (avoiding defects in consistence and flavour but keeping its tradition and tipicity). The study of the techniques used and the sensorial evaluation allowed to say that the production technique "a punta di coltello" and drying and ripening for three weeks at 12 degrees-15 degrees C and RU 75% are the best conditions to obtain "saisiccia sotto sugna" of excellent quality.

Artisanal manufactured sausage salsiccia sottosugna, produced according to traditional receipts, has been analysed in some areas of Basilicata region. During sausages making and ripening they have been drawn samples. For some products the microbiological analysis showed the potentiality for the selection of lactic acid bacteria and micrococci starters in order to improve the product (avoiding defects in consistence and flavour but keeping its tradition and tipicity). The study of the techniques used and the sensorial evaluation allowed to say that the production technique a punta di coltello and drying and ripening for three weeks at 12°-15°C and RU 75% are the best conditions to obtain salsiccia sotto sugna of excellent quality.

Sixty-six yeasts were isolated from seven samples of water-buffalo Mozzarella cheese. The yeast population ranged from 2x10(5) to 1x10(6) cfu/g. Among isolates, strains belonging to non-fermenting Candida spp., Saccharomyces cerevisiae and Kluyveromyces marxianus var. marxianus and var. lactis together with their anascosporogenous forms were identified. The dominant fermenting species were examined for production of secondary metabolites in synthetic medium and in milk. The fermenting yeasts were able to produce aromatic compounds other than ethanol, in particular ethyl acetate, which contributed significantly to the organoleptic characteristics of the cheese. In addition, the presence of non-lactose, but galactose fermenting S. cerevisiae can be useful in the reduction of residual sugars for the manufacture of low browning Mozzarella cheese.

A survey has been carried out on the technological, chemical and microbiological characteristics of artisanal produced salami, sausage and "soppressata", typical of the Lucania region. The technology of production has been analysed through a questionnaire directed to 6 sausage and 3 "soppressate" producers. During the samples drying the temperature and the relative humidify have been measured. During the storage of salami, vacuum-packed or in lard, the pH has been measured and have been carried out the microbial count of lactic acid bacteria, Micrococcaceae and yeasts. This microflora can be considered essential for the organoleptic and hygienic characteristics of this salami. Organoleptic tests have been carried out too. significative differences have been Found between the salami in relation to their origin and techniques of production.

A survey has been carried out on the technological, chemical and microbiological characteristics of artisanal produced salami, sausage and soppressata, typical of the Lucania region. The technology of production has been analysed through a questionnaire directed to 6 sausage and 3 soppressate producers. During the samples drying the temperature and the relative humidity have been measured. During the storage of salami, vacuum-packed or in lard, the pH has been measured and have been carried out the microbial count of lactic acid bacteria, Micrococcaceae and yeasts. This microflora can be considered essential for the organoleptic and hygienic characteristics of this salami. Organoleptic tests have been carried out too. Significative differences have been found between the salami in relation to their origin and techniques of production.