Proteolytic activity of Lactobacillus strains on soybean proteins

- Lactobacillus strains were able to hydrolyze soy proteins.
- α´subunit of β-conglycinin were the most degraded fraction.
- Peptidase activities were evaluated with different substrates.
- Lactobacilli strains showed different enzyme specificity on soy proteins.

The capacity of Lactobacillus strains for degrading soy proteins was evaluated. The hydrolytic action was monitored by SDS-PAGE and reverse phase-HPLC analyses. Peptidase activities were also determined using synthetic chromogenic substrates. All assayed strains were able to hydrolyze α'-subunit of β-conglycinin while for the other fractions the degree of degradation was strain-dependent. The pattern of peptides produced from soy proteins hydrolysis differed amongst the lactobacilli studied, suggesting different proteolytic enzyme specificities.