In press: Focus on Bacterial Mechanics, New Journal of Physics

All living organisms are subject to mechanical forces, while also generating such forces themselves. These forces shape their behavior on a broad range of length and time scales, from the molecular scale to the scale of whole organisms. Forces are key ingredients to the stepping of molecular motors, the motility of cells, the connectivity of tissues, morphogenesis and differentiation in development, and the activity and material properties of soft and hard tissues [1–6]. With the development of techniques to probe forces and to image deformations on the cellular level, the mechanics of cells has come to center stage over the last 30 years. For eukaryotic cells and tissues, such studies are now well established and form a core area of cellular biophysics.

The mechanical properties of bacteria and multicellular bacterial populations, however, have been studied much less and are much less understood. This discrepancy between our mechanical knowledge about eukaryotic cells and bacteria is mostly based on two interconnected reasons: one is the smaller size of bacteria, about an order of magnitude in linear size or three orders of magnitude in volume. This property meant that until recently, the intracellular structures of bacteria were below the resolution limit of optical microscopy. Related to that inability to observe intracellular structures such as a cytoskeleton or organelles was the widespread belief that such structures were absent in bacterial cells, which were often viewed as ‘bags of enzymes’… http://doi.org/10.1088/1367-2630/ab1505/