Microbial Stress Response in the Food Environment

Stress adaptation: bacterial cells adapt completely to the changed conditions, and growth rate is not affected. 2. ______ injury: may cause a transient adaptation (adaptive response) accompanied by a temporary physiological change that often results in increased stress tolerance. 3. Lethal stress: can cause the death of some, but not necessarily all, bacterial cells. When lethality is experienced by only a fraction of the population, accompanying gene responses and adaptive mutations may actually improve survival of the overall population. Stress Adaptation Stress adaptation or stress response has been explained as a situation whereby a brief exposure of a bacterial population to a suboptimal physical or chemical (growth) environment enables the cells to resist subsequent exposure to the same or other types of harsher treatment to which the species is normally susceptible. This phenomenon has been observed among many foodborne pathogens and spoilage bacteria following exposure of cells to various suboptimal physical and chemical Environments. Stress Adaptation It is assumed that a brief exposure to a suboptimal environment triggers some cellular mechanisms that enables them to resist subsequent exposure to harsher treatment.