Antibacterial activity of papain hydrolysed camel whey and its fractions

Camel whey (CW) was hydrolysed with papain from Carica papaya and fractionated by size exclusion chromatography (SEC). The antibacterial activity of the CW, camel whey hydrolysate (CWH) and the obtained SEC-fractions was assessed using the disc-diffusion method. The CWH exhibited significantly higher antibacterial activity than the unhydrolysed CW. SEC-F2 (fraction 2) exhibited the highest antibacterial activity against Staphylococcus aureus, whereas Escherichia coli was the least affected. Transmission electron microscopy (TEM) micrographs showed that the SEC-F2 caused changes in the treated bacterial cells. Additionally, LC/MS analysis was used to characterise the peptides profile of CW, CWH and SEC-F2. Two major peptides (414.05 and 456.06 Da mass) were detected in CWH and SEC-F2, with higher concentration in the latter. This study has demonstrated that hydrolysis of CW with papain generates a wide range of potent antibacterial peptides against selected pathogenic bacteria.