Identification of antibacterial and immunomodulatory bioactive peptides generated from buffalo (Bubalus bubalis) colostrum whey fermented by Lactobacillus rhamnosus C25: LC-MS/MS-based analysis

Abstract

Colostrum whey is rich in lots of bioactive protein like immunoglobulin, lactoferrin, lactoperoxidase, lysozyme etc. Colostrum whey with high protein concentration liberates higher amount of bioactive peptides which havea positive impact on physiological functions. In current report, several bioactive peptides were isolated from buffalo colostrum whey fermented using L.rhamonosus C25and simultaneously identified by SDS-PAGE and HPLC. The potent peptide sequences were identified by liquid chromatography with tandem mass spectrometry (LC-MS/MS) examination and further characterization was done based on their physico-chemical properties. Peptides fractions of 10 kDa, 5 kDa, and 3 kDa molecular weight were prepared from the fermentate and used to confirm their immunomodulatory potential and antimicrobial activity. Peptide fraction of <10 kDa (retentate) were having higher peptide content (0.625 mg/mL) and exhibited a remarkable immunomodulatory activity. Conversely, peptides fraction of <10 kDa (permeate) with low peptide content (0.421mg/mL) showed higher antimicrobial activity against diarrheagenic E. coli pathogens. Total 56 novel peptides were recognized after LC-MS/MS analysis where 16 peptides sequences such as VLVLDTDYK, GPFPIIV, VLVLDTDYKK were identified with antimicrobial activity and 40 peptides having embedded sequences like DMIVGPGNLQEGESEGDSQK, LGEYGFQNALIVR, CCAADDKEACFAVEGPK, showed a significant immunomodulatory potential. Thus, these bioactive peptides could be very promising ingredient to formulate a colostrum protein/peptides based formulation to treat E. coli induced diarrhea in immunocompromised persons.

Keywords

• Colostrum-whey
• Fermentation
• Bioactive-peptides
• Diarrhea
• Antimicrobial and Immunomodulatory activities