Casesidin-like anti-bacterial peptides in peptic hydrolysate of camel milk β-casein. (November 2018) - Almi-Sebbane, Dalila
Abstract: The antibacterial activity of camel milk β-casein and its peptic hydrolysate was investigated. The hydrolysate was fractionated by ultrafiltration successively through membranes with a 10 kDa and a 1 kDa cut-off, sequentially. Antibacterial activity assays against Staphylococcus aureus CNRZ 3, Listeria innocua ATCC 33090 and Escherichia coli ATCC 25922 were performed. The growth of S . aureus and L . innocua strain was not inhibited by β-casein; E . coli strain growth was slightly inhibited. All fractions of hydrolysates exhibited some anti-bacterial activity and molecular mass fraction <1 kDa was the most active against both Gram-positive bacterial strains. Mass spectrometry analysis revealed that this fraction contained 129 peptides. Interestingly, 2 of them, f(193–204) and f(193–213), presented at least 50% homology with casecidins 15 and 17 from bovine β-casein. This is the first study reporting the presence of two putative antibacterial fragments in camel β-casein peptic hydrolysate.