Various players in the nitrogen cycle: Diversity and functions of the microorganisms involved in nitrification and denitrification

Abstract Microorganisms play important roles in the nitrogen cycles of various ecosystems. Research has revealed that a greater diversity of microorganisms is involved in the nitrogen cycle than previously understood. It is becoming clear that denitrifying fungi, nitrifying archaea, anammox bacteria, aerobic denitrifying bacteria and heterotrophic nitrifying microorganisms are key players in the nitrogen cycle. Studies have revealed a major contribution by fungi in the production of N2O and N2 in grasslands, semiarid regions and forest soils. Some fungi can grow under various O2 conditions by using three types of energy-yielding metabolism: O2 respiration, denitrification (nitrite respiration) and ammonia…