Functional Groups of Microorganisms

Abstract

The living world is composed of three kingdoms: plants, animals, and microorganisms. The organisms of each kingdom play a key role in the functioning and maintenance of the Earth's ecosystems and biosphere (Fig. 4.1). Plant material, synthesized from CO2 with the help of solar energy, is consumed by animals and mineralized by microorganisms. Thus, the CO2 is reintroduced into the cycle. In other words, the key role of the heterotrophic microorganisms in the global carbon cycle is that of destruents of plant and animal biomass.