Action of Nisin and High Ph on Growth of Staphylococcus Aureus and Salmonella Sp. in Pure Culture and in the Meat of Land Crab (ucides Cordatus)

The aim of this study was to evaluate the potential of nisin and high pH to inhibit the growth of Staphylococcus aureus and Salmonella sp. in broth culture and when inoculated into meat of land crab. In pure cultures, the growth of S. aureus was strongly inhibited by nisin and the growth of Salmonella sp. was inhibited by nisin– EDTA (20 mM). The inhibition of S. aureus lasted for eight hours and Salmonella sp. growth was inhibited throughout the experiment (24 h). The high pH (pH 10.0 and 11.0 with NaHCO3-NaOH buffer) was very effective for in vitro inhibition of S. aureus and Salmonella sp. Nisin and high pH, when applied to the contaminated meat, did not yield the same effect. Nisin was not effective in preventing growth of both pathogens in the crab meat, while pH 10.0 showed significant inhibitory effect on Salmonella sp. The results suggest that high pH has a potential as antibacterial agent, and may be useful in chemical preservation of crab meat.