Use of PCR-based methods and PFGE for typing and monitoring homofermentative lactobacilli during Comté cheese ripening

• Published in: International journal of food microbiology Vol. 76; no. 1; pp. 27 - 38
• Main Authors: Bouton, Yvette, Guyot, Philippe, Beuvier, Eric, Tailliez, Patrick, Grappin, Rémy
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05.06.2002; Elsevier
• Subjects: Bacterial Typing Techniques; Biological and medical sciences; Cheese; Cheese - microbiology; DNA, Bacterial - analysis; Electrophoresis, Gel, Pulsed-Field; Fermentation; Food industries; Food Microbiology; Fundamental and applied biological sciences. Psychology; Genotype; Lactobacilli; Lactobacillus - classification; Lactobacillus - genetics; Life Sciences; Microbiology and Parasitology; Milk and cheese industries. Ice creams; PCR-ARDRA; PFGE; Phenotype; Phylogeny; Polymerase Chain Reaction; Random Amplified Polymorphic DNA Technique; RAPD; REP-PCR; RNA, Ribosomal, 16S - genetics; PCR-ARDRA; PFGE; Cheese; RAPD; REP-PCR; Lactobacilli; Cheese ripening; Lactic acid bacteria; Lactobacillus helveticus; Typing; Random amplified polymorphic DNA marker; Polymerase chain reaction; Microbiological investigation; Quality; Bacteria; Hard cheese; Lactobacillaceae; Lactobacillus delbrueckii subsp. lactis; Molecular biology; Viability; Monitoring; GENETIQUE
• ISSN: 0168-1605; 1879-3460
• DOI: 10.1016/S0168-1605(02)00006-5

This study investigated the genotypic characteristics of selected and wild homofermentative thermophilic lactobacilli strains during ripening of Comté cheeses, made into two cheese plants. Both amplification and restriction analysis of the 16S rRNA gene (PCR-ARDRA) and classical biochemical tests were used to identify isolates. Diversity within homofermentative lactobacilli was not found in their species composition since the same two species Lactobacillus helveticus and L. delbrueckii susbp. lactis were isolated from cheeses. In cheeses made with natural whey starter, it appeared that the most likely sources of L. helveticus and L. delbrueckii susbp. lactis were the starter and raw milk, respectively. The examination of RAPD profiles of lactobacilli strains revealed 19 RAPD groups among 50 isolates, which were different from selected starter strains. Using RAPD, REP-PCR, and PFGE to identify selected starter strains during cheese ripening, we showed that L. helveticus decreased quickly while L. delbrueckii susbp. lactis sustained high viability during ripening. The use of selected L. delbrueckii susbp. lactis strains diminished the genetic diversity among strains isolated from cheese, probably in preventing the raw milk microflora from growing.