CENTRO DE REFERENCIA PARA LACTOBACILOS
Unidad Ejecutora - UE
Functionality of lactic acid bacteria peptidase activities in the hydrolysis of gliadin like fragments
C.L.GEREZ; G. FONT DE VALDEZ; G.C. ROLLÁN
LETTERS IN APPLIED MICROBIOLOGY
Año: 2008 vol. 47 p. 427 - 427
Abstract Aims: To evaluate the role of the peptidase activities from sourdough lactic acid bacteria (LAB) in the degradation of á-gliadin-fragments. Methods and Results: Different proline-containing substrates were hydrolysed by LAB indicating Pro-specific peptidase activities. Lactobacillus plantarum CRL 775 and Pediococcus pentosaceus CRL 792 displayed the highest tri- and di-peptidase activities, respectively. Lact. plantarum strains hydrolyzed more than 60% á-gliadin-fragments corresponding to the 31-43 and 62-75 amino acids in the protein after 2 h. None of the LAB strains alone could hydrolyse 5789 á-gliadin-peptide; however, the combination of Lact. plantarum CRL 775 and P. pentosaceus CRL 792 led to hydrolysis (57%) of this peptide in 8 h. Conclusions: The capacity of LAB strains to degrade á-gliadin- fragments was not correlated to individual peptidase activities. Several strains separately, degraded the 31-43 and 62-75 á-gliadin-fragments, while the 5789 peptide degradation was associated to the combination of peptidase profiles from pooled LAB strains. This is the first report on the peptide hydrolase system of sourdough pediococci and its ability to reduce á-gliadin fragments. Significance and Impact of the Study: This study contributes to a better knowledge of sourdough LAB proteolytic system and its role in the degradation of proline rich á-gliadin peptides involved in celiac disease.