Diversity in proteinase specificity of thermophilic lactobacilli as revealed by hydrolysis of dairy and vegetable proteins

MICAELA PESCUMA; MARÍA BEATRÍZ ESPECHE TURBAY; FERNANDA MOZZI; GRACIELA FONT DE VALDEZ; GRACIELA SAVOY; ELVIRA MARÍA HÉBERT

APPLIED MICROBIOLOGY AND BIOTECHNOLOGY

SPRINGER

Lugar: Berlin; Año: 2013 vol. 97 p. 7831 - 7844

0175-7598

The ability of industrially relevant species of thermophilic lactobacilli strains to hydrolyze proteins from animal (caseins and beta-lactoglobulin) and vegetable (soybean and wheat) sources, as well as the influence of the peptide content of the growth medium on the cell envelope-associated proteinase (CEP) activity were evaluated. Lactobacillus delbrueckii subsp. lactis (CRL 581 and 654), Lactobacillus delbrueckii subsp. bulgaricus (CRL 454 and 656), Lactobacillus acidophilus (CRL 636 and 1063) and Lactobacillus helveticus (CRL 1062 and 1177) were grown in a chemically defined medium supplemented or not with 1% Casitone. All strains hydrolyzed mainly beta-casein while the degradation of alphas-caseins was strain-dependent. Contrariwise, kapa-Casein was poorly degraded by the studied lactobacilli. beta-lactoglobulin was mainly hydrolyzed by CRL 656, CRL 636 and CRL 1062 strains. The L. delbrueckii subsp. lactis strains, L. delbrueckii subsp. bulgaricus CRL 656 and L. helveticus CRL 1177 degraded gliadins in high extent while the L. acidophilus and L. helveticus strains hydrolyzed highly the soy proteins. Proteinase production was inhibited by Casitone being the L. delbrueckii subsp. lactis species the most affected. This study highlights the importance of the proteolytic diversity of lactobacilli for the rational strain selection when formulating hydrolyzed dairy or vegetable food products.