Biocrystallization of bacterial nucleoid under stress

Structural, biochemical, and genetic changes caused by stress factors are known to be largely similar for cells of all modern organisms, which inherited the basic strategies of adaptation to different types of stress from their ancient ancestors. In the present work, the adaptation process is considered for the simplest example of the bacterial E. coli nucleoid. Experimental studies performed recently on prokaryotic bacterial cells, the simplest living organisms, have demonstrated that, under unfavorable environmental conditions (for example, starvation), bacterial cells can use biocrystallization, a special mechanism of protection of the genetic apparatus (nucleoid), generally untypical of living organisms. This mechanism helps to protect the nucleoid from damage and resume the activity of the bacterial cells later, upon improvement of the external conditions. The results of studying the structure of the nucleoid of E. coli bacteria (BL21-Gold strain (DE3)) subjected to starvation stress by using synchrotron radiation at the ESRF beamline ID23-1 are reported.