Carbon dioxide (CO 2) is a safe and inexpensive gas that is used as a food additive. In this study, microbial control by pressurized CO 2 was examined. Pre-solubilization of CO 2 at 1 MPa at 4℃ markedly decreased the heat tolerance of vegetative bacterial cells through acidification of intracellular pH. Further, a 5-to 6-log reduction in vegetative bacterial cells was observed after incubation at around 60℃ for 1 min. The inactivation effect of pressurized CO 2 on bacterial spores was increased in the presence of monoglycerol monocaprate (MC10; 0.05 % w/v). The pressurized CO 2 accelerated MC10 adhesion to the spores as well as the release of dipicolinic acid from the spores, considerably decreasing physiological germination and/or heat resistance. When pressurized CO 2 was applied during the fermentation of sardine fish sauce, the salt concentration required for the inhibition of undesirable microorganism growth was reduced from 20 % to 10 %. In addition, the reduction of salt in fish sauce improved its nutritional and sensory qualities compared to that produced by the conventional method. These findings support the practical application of CO 2 for microbial control in foods and contribute to the development of improved food processing methods.