Short communication: Phenotypic and genetic diversity of wild Lactococcus lactis isolated from traditional Pecorino cheeses of Tuscany

• Published in: Journal of dairy science Vol. 96; no. 6; pp. 3558 - 3563
• Main Authors: Turchi, B., Van Tassell, M.L., Lee, A., Nuvoloni, R., Cerri, D., Miller, M.J.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2013
• Subjects: acidification; Animals; Cheese - microbiology; cheeses; DNA, Bacterial - analysis; DNA, Bacterial - chemistry; Ecology; enzyme activity; Fermentation; Genetic Variation; Hydrogen-Ion Concentration; Italy; Lactococcus lactis; Lactococcus lactis - classification; Lactococcus lactis - genetics; Lactococcus lactis - physiology; microbial ecology; milk; Milk - microbiology; multilocus sequence typing; Pecorino cheese; Peptide Hydrolases - metabolism; Phenotype; phylogeny; proteolysis; ribosomal DNA; RNA, Ribosomal, 16S - genetics; Sequence Analysis, DNA; Sheep; temperature; Italy; Lactococcus lactis; multilocus sequence typing; Pecorino cheese; microbial ecology
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.2012-6518

Wild Lactococcus lactis isolates from traditional Pecorino cheeses in 4 regions of Tuscany were isolated and characterized to evaluate the diversity of autochthonous lactococci. Sixty strains of Lactococcus were clustered by the results of carbohydrate utilization and diagnostic enzyme activity. Twenty-one unique strains were then chosen for characterization of salt and temperature tolerance, as well as acidification and proteolytic activity in milk. Genetic analysis of these strains was performed via 16S ribosomal DNA sequencing and multilocus sequence typing (MLST) to elucidate diversity relative to their location of origin. Phylogenetic analysis showed distinct clustering by region within organism subspecies, and phenotypic properties demonstrated concomitant trends. Multilocus sequence typing thus allowed for the regional distinction of isolates separate from those of previous works, supporting the concept that distinctive regional qualities of cheeses are strongly influenced by microbial ecology.