Abstract: Bacillus subtilis spores were suspended in phosphate buffer and treated by high-pressure carbon dioxide (HPCD) at the range of 5－25 MPa combined with mild heating. The results showed that Bacillus subtilis spores were inactivated by 3.84 magnitude orders after heating treatment for 30 min at 45 ℃ followed by treatment at 20 MPa for another 30 min. HPCD treatment alone resulted in an inactivation by 2.44 magnitude orders. Continuous HPCD treatment at 10 MPa for 30 min could result in a decrease in the viable spore count of Bacillus subtilis by 0.67 magnitude orders. After the first cycle of intermittent HPCD treatment (held at 10 MPa for 10 min and then at 30 min for another 10 min), Bacillus subtilis spores were inactivated by 2.55 magnitude orders. Meanwhile, the combined effects of each of three combinations of germination inducers and different combinations of heating and subsequent HPCD treatment (30 ℃ plus 10 MPa or 30 MPa and 50 ℃ plus 10 MPa or 30 MPa) were investigated. The inducing effect of germination inducers at 10 MPa was not so obvious as at 30 MPa.

Key words: high-pressure carbon dioxide, Bacillus subtilis spores, germination, inactivation