INFLUENCE OF SALTS AND MONTMORILLONITE UPON HEAT INACTIVATION OF POLIOVIRUS IN STERILE WATER

Using semi-purified type-1 poliovirus we show that the viral inactivat ion rate in sterile deionised water is not influenced by the initial v irus titer, remains unaffected by the saline concentration (ionic stre ngth) of the medium nor by the valency of the introduced cations. In t he presence of purified Na-montmorillonite and in similar conditions w e observe the same viral decay rates. In particular the presence of cl ay (at least up to 205 mg.l(-1)) does not provide viruses with any pro tective effect against heat, as experiments carried out at different t emperatures do not: reveal any difference between viral inactivation r ates due to the presence of montmorillonite. Furthermore viral decay r ates obtained with or without clay both plot against temperature on th e same regression line, following an Arrhenius-like equation with an e xcellent correlation coefficient.