text: AMGs have a large impact on biogeochemical cycles in multiple environments through nutrient degradation, mineralization, transportation, assimilation, and transformation. By enhancing the metabolic capabilities of their hosts, bacteriophages contribute to the recycling of organic matter, influencing the availability of nutrients for other organisms in the ecosystem. Lytic viruses in particular have been shown to increase ammonium oxidation, nitric oxide reduction, nitrification, and denitrification to balance nutrient levels in nitrogen polluted environments. Nutrient-enriched wetlands contain AMGs related to sulfur transport and metabolism. AMG modification of host processes is another means other than the viral shunt by which viruses can directly impact biogeochemical cycles.