Signals from cell control direction of rotation. Rotor is always spinning one direction or other. Energy for rotation comes from Proton gradient. If moving towards attractant, suppress tumbles. If moving away, increase frequ. of tumbles.
Many bacteria can survive for extended periods in absence of food, water, conditions for growth.
Can survive extended periods of dehydration. Allow prolonged survival, dispersal. Major source of difficulty with sterilization. Some resist boiling up to several hours. Spore is inert storage form.