INVESTIGADORES
MOZZI Fernanda Beatriz
congresos y reuniones científicas
Título:
Ability of thermophilic lactobacilli to hydrolyze food animal and vegetable proteins
Autor/es:
M. PESCUMA; M.B. ESPECHE-TURBAY; G. VIGNOLO; F. MOZZI; G. FONT DE VALDEZ; G. SAVOY DE GIORI; E.M. HEBERT
Reunión:
Simposio; FoodMicro 2012. 23rd International ICFMH Symposium. Global Issues in Food Microbiology; 2012
Resumen:
The cell envelope-associated proteinase (CEP) of lactobacilli has a key
role for bacterial nutrition and contributes to the development of the
organoleptic properties of fermented milk and vegetable products; moreover, it
can release bioactive health-beneficial peptides from milk proteins and
diminish allergic reactions. The aim of this study was to compare the ability
of industrially relevant species of thermophilic lactobacilli to hydrolyze
proteins from animal (caseins and β-lactoglobulin)
and vegetable (soybean and wheat) sources. In addition, the influence of the peptide
content in the growth medium on the CEP activity was evaluated. Lactobacillus delbrueckii subsp. lactis (CRL 581 and 654), L. delbrueckii subsp. bulgaricus (CRL 454 and 656), L. acidophilus (CRL636 and 1063) and L. helveticus (CRL 1062 and 1177) were
grown in a chemically defined medium supplemented or not with casitone (1%). Protein
hydrolysis was evaluated by SDS-PAGE and RP-HPLC. Proteinase production was
inhibited by casitone in different extent being this inhibition strain-dependent;
the L. delbrueckii subsp. lactis strains were the most affected (97-99%
inhibition) ones while L. acidophilus the
least influenced (33-50% inhibition). All strains hydrolyzed mainly β-casein while the degradation of α-casein was strain-dependent. Contrariwise, k-casein was poorly degraded by the all strains.
L. delbrueckii subsp. bulgaricus CRL 656, L. acidophilus CRL 636 and L.
helveticus CRL 1062 were able to hydrolyze the major milk allergenic
protein β-lactoglobulin
while L. delbrueckii subsp. lactis
strains, L. delbrueckii subsp. bulgaricus CRL 656 and L. helveticus CRL 1177 degraded the gliadin
cereal protein in a higher extent. Respect to soy proteins, the L. acidophilus and L. helveticus strains showed the lowest proteolytic ability. This
study deepens into the understanding of the proteolytic diversity of lactic
acid bacteria for exploiting this complex system in the manufacture of novel
functional foods. The rational selection of proper strains when formulating
hydrolyzed food products of different origin (dairy or vegetable) is of utmost
importance since proteinases specificities are strain-dependent.