Thermal inactivation of blue tongue virus

Summary

The thermostability of blue tongue virus at various storage conditions and temperatures of inactivation was studied at pH 7.0. The virus was markedly thermostable, withstanding 3 years storage at room temperature. Thermal inactivation curves suggested first-order kinetics, with two components at 37, 46 and 56° C but only one at −70° C. The two-component curves were most likely due to a phenotypically determined heterogeneity of the virus population with respect to thermostability. While inactivation at high temperatures (46–56° C) was associated with marked changes in enthalpy and entropy, compatible with protein inactivation, the thermodynamic data obtained at a lower temperature range (37–46° C) suggested ribonucleic acid inactivation. Approximate energy of activation values below and above 37° C were 7.5 and 50 kcal. mole⁻¹ respectively.