Characterization of natural starter cultures used in the manufacture of Pasta Filata cheese in Basilicata (Southern Italy)

Microbiological, chemical and technological analyses were used to characterize nine natural starter cultures used for the manufacture of Pasta Filata cheese in Basilicata (Southern Italy). The cultures were either dominated by thermophilic rods or mesophilic and/or thermophilic cocci. Principal component and cluster analysis discriminated between rods and coccus cultures and helped to estabilish relationships between the cultures and to evaluate the variability of cultures obtained from the same plant. A total of 156 isolates of lactic acid bacteria were obtained from the cultures and tentatively classified using biochemical and physiological tests and cluster analysis. Most of the lactobacilli were identified as Lactobacillus helveticus. Most cocci were classified in the genera Lactococcus or Enterococcus but identification at the species level was often impossible. The acid production and proteolytic activity of the isolates in skim milk were evaluated. Cluster analysis was used to group the isolates according to technological properties. Isolates belonging to some phenotypic clusters were consistently associated with some technological clusters. (C) 1998 Elsevier Science Ltd. All rights reserved.