The process begins with anaerobic bacteria, leading to fermentations, which increases the temperature, even reaching 70ºC. Later, when oxygen is more and more present, the temperature drops, anaerobiosis slows down and even stops, disappearing the anaerobic, thermophilic organisms, replaced by the aerobic, mesophilic ones. Actinomycetes and aerobic fungi finish preparing the substrate, finishing the composting process by microorganisms.