Characterization of Certain Bacterial Strains for Potential Use as Starter or Probiotic Cultures in Dairy Products

• Published in: Journal of food protection Vol. 74; no. 8; pp. 1379 - 1386
• Main Authors: MONTEAGUDO-MERA, A, CARO, I, RODRIGUEZ-APARICIO, L. B, RUA, J, FERRERO, M. A, GARCIA-ARMESTO, M. R
• Format: Journal Article
• Language: English
• Published: Des Moines, IA International Association for Food Protection 01.08.2011; Elsevier Limited
• Subjects: Acidification; Acids; Animals; Antimicrobial agents; Bacteria; Biological and medical sciences; Cattle; Colony Count, Microbial; Dairy products; Dairy Products - microbiology; Enterococcus faecalis; Enterococcus faecalis - physiology; Enzymatic activity; Enzymes; Feces; Fermentation; Food contamination & poisoning; Food industries; Food Microbiology; Food safety; Fundamental and applied biological sciences. Psychology; Glucose; Humans; Lactobacillus - physiology; Lactobacillus casei; Lactobacillus paracasei; Lactobacillus rhamnosus; Lactococcus - physiology; Lactococcus lactis; Leuconostoc - physiology; Leuconostoc mesenteroides; Milk; Milk - microbiology; Milk and cheese industries. Ice creams; Probiotics; Sheep; Species Specificity; Statistical analysis; Virulence; Characterization; Probiotic; Dairy product; Use; Strain
• ISSN: 0362-028X; 1944-9097
• DOI: 10.4315/0362-028X.JFP-10-392

The present work was aimed at characterizing 12 strains of lactic acid bacteria (LAB) to obtain improved potential starter or probiotic cultures that could be used for making dairy products from ewe's milk and cow's milk. Eight strains with antimicrobial properties, isolated from ewe's milk and from cheese made from ewe's and/or cow's milk, were studied. They were identified as Enterococcus faecalis (five strains), Lactococcus lactis subsp. cremoris, Leuconostoc mesenteroides, and Lactobacillus paracasei subsp. paracasei (one strain of each species). Additionally, four strains were obtained from the American Type Culture Collection: Lactobacillus casei 393 (isolated from cheese), L. lactis subsp. lactis 11454 (origin nonspecified and a producer of nisin), and two strains isolated from human feces (L. paracasei subsp. paracasei 27092 and Lactobacillus rhamnosus 53103, antibacterial agent producer). All E. faecalis strains showed at least one virulence factor (either hemolysin or gelatinase), which emphasizes the importance of these studies in this species. Both L. lactis strains and most Lactobacillus spp. were good acidifiers in ewe's milk and cow's milk at 30°C. High β-galactosidase activity, as well as aminopeptidase activities that favor the development of desirable flavors in cheese, were detected in all Lactobacillus spp. strains. Furthermore, L. rhamnosus ATCC 53103 showed α-fucosidase activity (thought to help colonization of the intestine) and lack of α-glucosidase activity (a trait considered positive for diabetic and obese humans). This last enzymatic activity was also lacking in L. lactis ATCC 11454. L. mesenteroides was the only strain D(2)-lactic acid producer. The selection of any particular strain for probiotic or dairy cultures should be performed according to the technological and/or functional abilities needed.