Monitoring of the bacterial composition of dairy starter cultures by RAPD-PCR.
Randomly amplified polymorphic DNA (RAPD)-PCR was used to verify the species composition of commercial dairy starters and to detect possible shifts in strain composition of these cultures. After RAPD-PCR analysis, not all the strains isolated in the years 2001 and 2002 fell within the same dendrogram cluster of the strains isolated in the year 2000 and used as reference strains. Changes in composition of the microbial population and/or voluntary immission of new biotypes with respect to the original strain formulation had occurred in the starters. The microbial composition of modern dairy starters represents a key point because the complex relationships among microorganisms can easily be altered. Little variations in the microbial composition could have unexpected effects on cheese quality.
Department of Microbiology and Enzymology, Istituto Sperimentale Lattiero Caseario, Via A. Lombardo 11, 26900 Lodi, Italy. ggiraffa@iclodi.it
Giorgio
G
Giraffa
Lia
L
Rossetti
D001419:Bacteria / Q000145:classification* / Q000235:genetics*; D015373:Bacterial Typing Techniques; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000032:analysis / Q000302:isolation & purification; D003611:Dairy Products / Q000382:microbiology*; D005516:Food Microbiology; D017045:Lactococcus / Q000145:classification / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique; D013291:Streptococcus / Q000145:classification / Q000235:genetics
D004269:DNA, Bacterial