My wife is a kindergarten teacher. She always talks about how stressful her job is, and I believe her. Stress can have horrible effects to our bodies. However, humans are not the only species that experience stress, but we are the most vocal about it.
Bacteria can experience many different forms of stresses, depending upon their environment. Temperature, pH, and dryness (desiccation) are common forms of bacterial stress. When bacteria sense something is not right in their environment, they must decide what the appropriate action is to assure their survival. For example, many bacteria find high concentrations of oxygen harmful. Atmospheric oxygen (O2) can inhibit enzyme action for several vital enzymes including NiFe nitrogenase that converts atmospheric nitrogen (N2) into a usable nitrogen form (ammonium). In this case, the presence of oxygen competes with N2 for electrons from nitrogenase producing water instead of ammonium. This can lead to nitrogen starvation and the inability to synthesize new proteins. To avoid this, cells must change their lifestyle from loners to a well connected community via aggregation. Once cells are aggregated together, they can produce a protective layer of sugar polymers on the outside of the cells to buffer the cells themselves from oxygen. Crisis averted! Now the cells are able to survive but at a lower growth rate.
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