How does moist heat inactivate microorganisms?

                                                                                                         Book chapter – Steam Sterilization: A Practitioner’s Guide (Ch.01)

Microorganisms are living organisms, and the environment in which they livecan positively and negatively affect them. The environmental stress exerted on the microorganism leads to specific responses, dependent upon the organism species, the strain, the methods and media used to culture the organisms, the environmental conditions to which the organism was exposed during the stress condition, and the source or type of stress (Pflug 1999).
When one subjects a microorganism to a stress condition or agent, attempting to inactivate the microorganism, the results may be variable depending upon the stress agent (Russell 1993).

Furthermore, each stress condition or agent used to inactivate microorganisms has a specific mechanism via which the cell is inactivated (Pflug 1999). This chapter is devoted exclusively to using moist heat sterilization as a method of microbial inactivation. These principles may not be applicable to other types of sterilization agents, e.g., dry heat, ethylene oxide, chemical agents, and radiation.

Conclusion

Bacterial cells can be affected by their environment. Moist heat sterilization can be used to inactivate the microorganisms by dehydration, mineralization/demineralization, or adaptation. […].