Thermal stability of bacteriophage ST1 was investigated by testing its survival under different temperatures (50, 60, 70 and 80°C) for 3 min. No significant change of bacteriophage titer was observed when the bacteriophage was treated at 50 and 60°C. However, the bacteriophage titer was found to drop from about 6 log PFU/ml to about 5 and 4 log PFU/ml after heating the bacteriophage at 70 and 80°C, respectively. No completely elimination of the bacteriophage was observed in all temperature treatments (Table 2).