The Micro-Organisms in the Air

Of all environmental, air is the simplest one and it occurs in a single phase, gas. Air is not a natural environment for the growth and reproduction of microorganisms. It does not contain necessary amount of moisture and utilizable form of nutrient. In addition to gasses, dust particles and water vapour, air also contains microorganisms. There are vegetative cells and spores of bacteria, fungi and algae, viruses and protozoan cysts.