Brazilian artisanal ripened cheeses as sources of proteolytic lactic acid bacteria capable of reducing cow milk allergy
Résumé
AimThe objective was to obtain lactic acid bacteria (LAB) capable of hydrolysing immunoreactive proteins in milk, to optimize the hydrolysis, to determine the proteolysis kinetics and to test the safety of the best hydrolytic strain. Methods and ResultsBrazilian cheese was used as source of Lcapable of hydrolysing main milk allergens. Proteolytic isolates were submitted to RAPD-PCR for the characterization of clonal diversity. Optimized hydrolysis was strain and protein fraction dependent. 16S rDNA sequencing identified three proteolytic strains: Enterococcus faecalis VB43, that hydrolysed (S1)-, (S2)- and -caseins, -lactalbumin and -lactoglobulin (partial hydrolysis), and Pediococcus acidilactici VB90 and Weissella viridescens VB111, that causedpartial hydrolysis of (S1)- and (S2)-caseins. Enterococcus faecalis VB43 tested negative for virulence genes asa1, agg, efaA, hyl, esp, cylL(L) and cylL(S) but positive for genes ace and gelE. Ethylenediamine tetra-acetic acid inhibited the proteolysis, indicating that the main proteases of E. faecalis VB43 are metalloproteases. ConclusionBrazilian artisanal cheese is a good source of Lcapable of hydrolysing allergenic proteins in milk. One isolate (E. faecalis VB43) presented outstanding activity against these proteins and lacked most of the tested virulence genes. Significance and Impact of the StudyEnterococcus faecalis VB43 presents good potential for the manufacture of hypoallergenic dairy products.