INVESTIGADORES
RAYA Raul Ricardo
artículos
Título:
Characterization of natural isolates of Lactobacillus strains to be used as starter cultures in dairy fermentation
Autor/es:
HÉBERT EM, RAYA RR, TAILLIEZ P, DE GIORI GS.
Revista:
INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam, The Netherlands; Año: 2000 vol. 59 p. 19 - 27
ISSN:
0168-1605
Resumen:
The technological relevant characteristics of five homofermentative
lactobacilli strains, isolated from natural fermented hard cheeses, were
studied. Isolates CRL 581 and CRL 654, from Argentinian artesanal hard
cheeses, and isolates CRL 1177, CRL 1178, and CRL 1179, from Italian
Grana cheeses, were identified as Lactobacillus delbrueckii subsp.
lactis and Lactobacillus helveticus, respectively, by physiological and
biochemical tests, SDS-PAGE of whole-cell proteins and sequencing of the
variable (V1) region of the 16S ribosomal DNA. All strains showed high
levels of beta-galactosidase activity. However, proteolytic activity
varied widely among isolates. Strains CRL 581, CRL 654, and CRL 1177
hydrolyzed alpha- and beta-caseins and were able to coagulate
reconstituted skim milk in less than 16 h at 42 degrees C. According to
the substrate specificity, these proteinases have a caseinolytic
activity comparable to that of the P(III)-type of lactococcal
proteinases. No strains produced inhibitor substances (bacteriocin) and
all were insensitive to attack by 14 L. helveticus- and L. delbrueckii
subsp. lactis-specific bacteriophages.