[Screening of thermophilic superoxide dismatase producing strain and some properties of the enzyme].

A thermophilic SOD producing strain was obtained from the bacteria preserved in our lab. Its content of SOD was 8774u/g fresh cells. The strain can tolerate 0.4% H2O2 and 70 degrees C, and it has outstanding culture characteristics. It was identified as Bacillus stearothermophilus, called B.S 211-15. Crude SOD was extracted from B.S 211-15, the recovery of total activity was 69.5%, the specific activity was 1793u/mg protein. The enzyme showed fine heat stability, pH stability and good proteinase resistance. The SOD activity didn't decrease after being kept in room temperature for 2 months. The results of inhibition reactions indicated that this enzyme was Fe-SOD.