INVESTIGADORES
MOZZI Fernanda Beatriz
congresos y reuniones científicas
Título:
Lactobacillus acidophilus CRL 636 and Lactobacillus delbrueckii subsp. bulgaricus CRL 656 hydrolyse the main epitopes of beta-lactoglobulin
Autor/es:
M. PESCUMA; E.M. HEBERT; M. DALGALARRONDO; J.C. GAUDIN; T. HAERTLE; F. MOZZI; J.M. CHOBERT; G. FONT DE VALDEZ
Reunión:
Simposio; III Simposio Internacional de Bacterias Lácticas. II Encuentro RED BAL Argentina; 2009
Resumen:
β-Lactoglobulin (BLG) is the main whey protein and a
major milk allergen. The main epitopes identified to be responsible for allergy
especially in children under 3 years old are 41-60, 102-124 and 149-162. Whey
is commonly added to milk in infant formula to assemble the ratio between
caseins and whey proteins to that of human milk. Several efforts have been made
to reduce the BLG allergenic content including denaturation (heat, high
pressure) and hydrolysis of this protein by several methods (enzymatic, chemical).
Lactic acid bacteria are food grade microorganisms able to hydrolyze milk
proteins. The aim of this work was to develop a lactic starter culture capable
of hydrolyzing the BLG epitopes to reduce its allergenicity. The ability of a
starter culture (named LaB) composed of Lactobacillus
acidophilus CRL 636 and Lactobacillusdelbrueckii ssp. bulgaricus CRL 656 (ratio 3:1), which is known to degrade BLG, was
evaluated in a non-proliferating cell system. Briefly, cells were grown in a
chemically defined medium, harvested at the exponential growth phase, starved,
concentrated, and incubated with pure BLG for 8 h. Protein degradation was
analyzed by Tricine SDS-PAGE, RP-HPLC and LC-MS/MS and the reactivity of
hydrolyzates was evaluated using the ELISA test. The culture LaB hydrolyzed 56%
of BLG releasing peptides of 11.3, 10.1, 9.5, 8.7 and 6.9 kDa. The RP-HPLC
analysis showed the release of one hydrophobic peptide (eluted at 32 min), four
main peaks eluting between 16 and 26 min and one hydrophilic peptide (eluted at
6 min). Twenty three peptides coming from the BLG hydrolysis were identified by
LC-MS/MS. The sequence analysis revealed that the LaB culture was able to
degrade the three main BLG epitopes. The ELISA test using sera from BLG
allergenic patients (2 to 6-years old children) showed that the BLG hydrolysates
were less reactive than the untreated protein. The starter LaB enables the
production of BLG hydrolysates with reduced allergenicity to be used as food
additives or ingredients.