Comparison of the antibacterial activity of the hypothiocyanite anion towards Streptococcus lactis and Escherichia coli.

It has been suggested that the antibacterial activity of the lactoperoxidase/thiocyanate/hydrogen peroxide system is due to the hypothiocyanite anion. Relatively pure solutions of hypothiocyanite can be prepared using an immobilized enzyme. These preparations have been used to examine the effect of the anion on the growth and on the membranes of Escherichia coli and Streptococcus lactis. Escherichia coli is killed in the presence of the anion whereas the effect on Streptococcus lactis is only bacteriostatic. As similar effects have been noted with the lactoperoxidase/thiocyanate/hydrogen peroxide system the hypothesis that the action of the two systems is similar is supported.