Archaea, particularly methanogens, are the main producers of methane through the anaerobic decomposition of organic matter in environments such as wetlands and landfills.

Cellular respiration is the process by which microorganisms break down organic compounds, such as glucose, to produce energy in the form of ATP, releasing carbon dioxide as a byproduct.

Nitrification is the process by which microorganisms convert ammonia into nitrate, removing carbon dioxide from the atmosphere and contributing to the nitrogen cycle.

Anaerobic respiration is the process by which microorganisms obtain energy from organic compounds without the presence of oxygen, releasing various products such as methane, carbon dioxide, and hydrogen sulfide.

Nitrogen fixation is the process by which certain microorganisms convert atmospheric nitrogen into ammonia, making it available for plant growth and other biological processes.

Methanogenesis is the process by which certain microorganisms, known as methanogens, convert organic matter into methane, a potent greenhouse gas.

Denitrification is the process by which microorganisms convert nitrate into nitrogen gas, releasing nitrous oxide as a byproduct.

Aerobic respiration is the process by which microorganisms obtain energy from organic compounds in the presence of oxygen, releasing carbon dioxide and water as byproducts.

Sulfate reduction is the process by which certain microorganisms convert sulfate into hydrogen sulfide, a toxic gas with a pungent odor.

Fermentation is the process by which microorganisms convert organic compounds into alcohol or organic acids in the absence of oxygen.

Carbon monoxide production is a microbial process by which certain microorganisms convert organic matter into carbon monoxide, a toxic gas.

Hydrogen production is a microbial process by which certain microorganisms convert organic matter into hydrogen gas.

Sulfur oxidation is a microbial process by which certain microorganisms convert organic matter into elemental sulfur.

Denitrification is the process by which certain microorganisms convert nitrate into nitrogen gas, releasing nitrous oxide as a byproduct.

Ammonia production is a microbial process by which certain microorganisms convert organic matter into ammonia, a toxic gas.