Pediocin PA-1 containing fermented cheese whey reduces total viable count of raw buffalo (Bubalis bubalus) milk

Abstract

The present study was carried out to enhance shelf life of raw buffalo milk by the use of pediocin PA-1 containing fermented cheese whey (PCFCW) as bio-preservative. Ten distinct genera of milk microbes could be identified as Streptococcus, Enterococcus, Salmonella, Campylobacter, Lactobacillus, Enterobacter, E. coli, Shigella, Candida and Aspergillus. For the production of PCFCW, supplemented cheese whey medium was fermented with Pediococcus pentosaceous NCDC 273 for 24 h. Partially purified PCFCW was prepared using ammonium sulphate precipitation followed by membrane ultrafiltration with 10 kDa and 3 kDa membrane (Millipore) respectively. The fraction between 10 and 3 kDa was used as bio-preservative. This bio-preservative was found to contain pediocin PA-1 at the level of 2.04 × 105 AU/ml. In view of the wide antibacterial spectrum of pediocin, the PCFCW formulation was added at 1%, 5%, and 10% (v/v) concentrations to raw buffalo milk to reduce total microbial load. A significant decrease (p˂0.05) was observed in total viable count on TGYEA, Staphylococcus aureus count on BPA, and lactic acid bacterial count on MRSA. However, the reduction in coliform count on VRBA and yeast-mould count on PDA was non-significant (p˂0.05). Therefore, it can be concluded that partially purified PCFCW was effective in reducing total microbial load in raw buffalo milk.