<P> Microbial metabolism is the means by which a microbe obtains the energy and nutrients (e.g. carbon) it needs to live and reproduce . Microbes use many different types of metabolic strategies and species can often be differentiated from each other based on metabolic characteristics . The specific metabolic properties of a microbe are the major factors in determining that microbe's ecological niche, and often allow for that microbe to be useful in industrial processes or responsible for biogeochemical cycles . </P> <P> All microbial metabolisms can be arranged according to three principles: </P>

What nutrient is the main source of energy for microorganisms