The biotransformation of elements from raw material to nutrients or to energy is important in sustaining the nutrient cycles which are the basis of all food chains. The assimilation of elements such as nitrogen, phosphorous give a ready supply of fresh material to sustain the food chains. Because of the close proximity to the material and in the nature of how elements enter into the food chains by the metabolic and energy pathways, this process is carried out largely by microorganisms. Whilst it is convenient to consider each cycle on its own, no cycle operate independently. 

Many biological systems are involved in the processing of weathered rock material. This eventually contributes to soil formation through the deposition of organic material from the organisms (see soil formation).