Chiang Mai Journal of Science

This aims of this report were to evaluate Streptococcus bovis RMM 902 as a bacteriocin producer, to carry out partial characterization and purification of the bacteriocin, and to investigate its antibacterial activity against variety of pathogenic bacteria. A bacteriocin producer strain was evaluated for antibacterial activity against a variety of pathogenic bacteria. Effects of temperature and pH on bacteriocin activity were studied. The bacteriocin was purified by ammonium sulfate precipitation and ion exchange chromatography. The bacteriocin activity was tested at each step of purification. The inhibitory activity of Streptococcus bovis RMM 902 was demonstrated against some Gram positive and Gram negative bacteria such as S. dysgalactiae, Listeria monocytogenes, Salmonella typhi and Salmonella enteritidis. The inhibitory activity was presented over a broad range of pH and tolerant to high temperature. Purification with ammonium sulfate precipitation increased the antibacterial activity from 80 to 640 AU/ml with a 5.3 fold purification factor. Ion exchange chromatography increased purification factor to 35.5 fold and the bacteriocin was sized at less than 3,400 Da. The bacteriocin isolated from Streptococcus bovis RMM 902 was shown to provide effective control on pathogenic bacteria.  There is the potential to use this bacteriocin for the prevention of bovine mastitis caused by S. dysgalactiae and potentially could be used as a food preservative.