Shock waves can enhance bacterial transformation with plasmid DNA

Shock waves appear in nature whenever the different elements in a fluid approach one another with a velocity larger than the local speed of sound. Shock waves are strong perturbations in aerodynamics that propagate at supersonic speeds independent of the wave amplitude. Such disturbances occur in steady transonic or supersonic flow during explosions, lightening strokes and contact surfaces in laboratory devices. The typical thickness of the shock front in air is $~10^{\mathrm{-7}}m$, very small compared to other characteristic lengths in fluid flow. Physically, the occurrence of shock waves is always characterized in a fluid flow by instantaneous changes in pressure, velocity and temperature