Peptidomic study of casein proteolysis in bovine milk by Lactobacillus casei PRA205 and Lactobacillus rhamnosus PRA331

Abstract

Lactobacilli contain different cell envelope proteinases (CEPs) responsible for the hydrolysis of caseins and the release of various bioactive peptides. In this work, we explored the CEP activity of Lactobacillus casei PRA205 and Lactobacillus rhamnosus PRA331 whole cells towards β-, αS1-, κand αS2-caseins in bovine milk. Mass spectrometry analysis of fermented milk hydrolysates identified a total of 331 peptides, which were mainly derived from β-caseins (59.0 and 60.1% for PRA205 and PRA331, respectively). The analysis of αS1-casein (f1-23) cleavage site specificity congruently supports that Lb. casei PRA205 and Lb. rhamnosus PRA331 exhibited a mixed-type CEPI/III activity. PRA205 and PRA331 CEPs also showed cleavage site specificity toward β-casein, preferentially. These CEPs cleaved the peptide bond preferentially when hydrophobic or negatively charged amino acids were present. 13.5% and 13.7% of peptides released by Lb. casei PRA205 and Lb. rhamnosus PRA331 CEPs were found to have 100% homology with previously identified bioactive peptides.

Development of Antioxidant and Antihypertensive Properties during Growth of Lactobacillus helveticus, Lactobacillus rhamnosus and Lactobacillus reuteri on Cow’s Milk: Fermentation and Peptidomics Study

“…While the strain L. helveticus NK1 demonstrated comparable proteolytic activity to those previously reported for this LAB species [18,19], the strain L. rhamnosus F studied in this work showed a higher proteolytic activity than those described in the literature-the L. rhamnosus PRA331 strain after 72 h of fermentation on milk had a proteolytic activity of 6.4 mM (Leu) (pH 4.0) [20]. Unfortunately, no comparable data on the proteolytic activity of L. reuteri have been previously published.…”

Influence of co-cultures ofStreptococcus thermophilus and probiotic lactobacilli on quality and antioxidant capacity parameters of lactose-free fermented dairy beverages containingSyzygium cumini(L.) Skeels pulp

“…13 In another study, Santos and co-workers 16 veried that relative amount of low-molecular-weight protein fractions (<6.5 kDa) increased in reconstituted goat whey powder fermented with co-cultures of S. thermophilus TA-40 with L. casei BGP93 or L. rhamnosus LR32 stored for 7 days at 4 C; however, according to the authors, the pattern of degradation of goat whey proteins during storage differed between those trials, particularly for fractions of 50-90 kDa that only reduced in the TA-40 plus BGP3 trial. Solieri and co-workers 43 evaluated the proteolytic capacity of strains of L. casei PRA205 and L. rhamnosus PRA331 in fermented milk and observed the production of peptides, highlighting the specicity of each bacterial strain in the proteolysis prole, as shown in the present study. In general, proteolysis in dairy products consists of protein degradation performed by endogenous milk enzymes and enzymes originating from lactic acid bacteria, which results in the production of low-and medium-molecular weight peptides and free amino acids.…”

Peptide Profiling and Biological Activities of 12-Month Ripened Parmigiano Reggiano Cheese

“…Therefore, it was possible that peptides released from the C-terminus were hydrolyzed to shorter peptides by the action of LAB CEPs and LAB endopeptidases. Despite peptide Y 193 -V 209 can be originated by the action of chymosin [ 6 ], most of the C-terminus peptides derived from CEPs hydrolysis, as depicted by the numerous characteristic CEPs cleavage sites [ 52 , 53 , 54 ].…”