In conclusion all microbes need space to grow, move, and reproduce. Water is a requirement; and micro-organisms that are exposed to low water activity will die or become dormant. In nature, some microbes are halphiles and survive best in environments with 1-15% salt. Halobacterium grows best in 15% salt concentration; Vibrio grows best at 3% salt concentration; E.coli is not tolerant of salt but Staphylococcus will tolerate salt and grow on mannitol salt agar with a 7.5% salt concentration. Microbes have a wide variety of growth requirements; and nature provides a "home" for each microbe. So at the bottom of the ocean, in the tundra snow drifts, in the Hot Springs of Arkansas, in outer space (perhaps microbes are on Mars), in the stomach of a cow, on your skin, in the gut of a fish, and all other habitats on earth you would find some microbe surviving and "doing fine."