HomePhilippine Journal of Veterinary and Animal Sciencesvol. 35 no. 1 (2009)

Growth Inhibition Of Pathogenic Bacteria By Lactoferrin Pepsin Hydrolysate Fractions From Milk Of Carabao (Bubalus bubalis L.)

Amado A. Angeles | Florinia E. Merca | Nieva T. Librojo-basilio | Ninfa P. Roxas | Florante A. Cruz

Discipline: Veterinary Medicine, Animal Science



Purified carabao’s milk lactoferrin (cLF) previously shown to inhibit growth of enteropathogenic E. coli and S. Typhimurium was hydrolyzed with porcine pepsin to determine the fractions with growth inhibitory activity. Carabao’s milk LF pepsin hydrolysate (cLFH) fractions were separated by cation exchange chromatography-carboxymethyl cellulose (CEC-CMC). Molecular weights of fractions were estimated by sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE). Growth inhibition using the micro-dilution technique against enteropathogenic E. coli (EPEC) and S. Typhimurium in vitro at varying pH and temperature were also tested. The cLFH loaded on CEC yielded 3 peaks after elution with 0.0–1.0 M NaCl gradient. The cLFH 1, 2 and 3 were eluted at salt concentration ranges of 0.02- 0.04 M, 0.08-0.12 M and 0.4-0.55 M, respectively. SDS-PAGE showed fractions with MW of 6,500 and below with cLFH 2 and 3 relatively larger than cLFH 1. Results of the growth inhibitory test show that cLFH 1 had the highest growth inhibition of EPEC and S. Typhimurium with minimal inhibitory concentration of 25 μg/ml compared to 100-200 μg/ml for cLFH 2 and 3, respectively. Growth inhibitory activities of cLF and its cLFH fractions against EPEC and S. Typhimurium were stable from pH 3-7 and up to 80ºC.