Proteolytic activity and reduction of gliadin-like fractions by sourdough lactobacilli.
OBJECTIVE
To characterize the peptide hydrolase system of Lactobacillus plantarum CRL 759 and CRL 778 and evaluate their proteolytic activity in reducing gliadin-like fractions.


RESULTS
The intracellular peptide hydrolase system of Lact. plantarum CRL 759 and CRL 778 involves amino-, di- (DP), tri- (TP) and endopeptidase activities. These peptidases are metalloenzymes inhibited by EDTA and 1,10-phenanthroline and stimulated by Co2+. DP and TP activities of Lact. plantarum CRL 759 and CRL 778, respectively, were completely inhibited by Cu2+. Lactobacillus plantarum CRL 778 showed the highest proteolytic activity and amino acids release in fermented dough. The synthetic 31-43 alpha-gliadin fragment was hydrolysed to 36% and 73% by Lact. plantarum CRL 778 and CRL 759 respectively.


CONCLUSIONS
Lactobacillus plantarum CRL 759 and CRL 778 have an active proteolytic system, which is responsible for the high amino acid release during sourdough fermentation and the hydrolysis of the 31-43 alpha-gliadin-like fragment.


CONCLUSIONS
This work provides new information of use when obtaining sourdough starters for bread making. Moreover, knowledge regarding lactobacilli capable of reducing the level of gliadin-like fractions, a toxic peptide for coeliac patients, has a beneficial health impact.
Rollán
G
G
Centro de Referencia para Lactobacilos (CERELA), CONICET, Chacabuco, Tucumán, Argentina. rollan@cerela.org.ar
De Angelis
M
M
Gobbetti
M
M
de Valdez
G F
GF
D000596:Amino Acids / Q000378:metabolism; D001939:Bread / Q000382:microbiology*; D015169:Colony Count, Microbial; D005285:Fermentation; D005516:Food Microbiology; D005524:Food Technology / Q000379:methods*; D005903:Gliadin / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007778:Lactobacillus / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000032:analysis* / Q000378:metabolism; D013696:Temperature
D000596:Amino Acids; D005903:Gliadin; D010447:Peptide Hydrolases