Oxygenation on Earth Likely Originated from Microbes and Minerals

Oxygen is an important chemical element inhaled by most living organisms in order to sustain bodily functions, including growth and reproduction. The abundance of oxygen in contemporary times is the opposite of the amount of oxygen when Earth formed around 4.5 billion years ago.

The mystery behind the emergence of oxygen, also known as oxygenation, has baffled the scientific community for centuries-as the significant oxygen supply that was are seeing today is nowhere to be found during the first 2 billion years of Earth since its formation.

However, a new study suggests marine microbes and minerals in ocean sediments may be the key to oxygenation or the phenomenon of what is called the Great Oxidation Event-wherein the atmosphere and oceans were filled by paramount levels of oxygen, enough to create and support life.

Oxygenation

In a new study published in the journal Nature Communications on Monday, March 14, researchers from the Massachusetts Institute of Technology (MIT) said oxygenation is caused by oxidative metabolisms generated by the interaction between marine microbes and minerals in ocean sediments.

Amid the myriad of theories on the origin of oxygenation, the study sheds light on the fact that the combination of biological and geological processes have paved the way for the increased build-up of oxygen-which started an era of a conducive environment and climatic conditions to support life.

New Hypothesis

The MIT researchers hypothesized the matter from oxidative metabolisms called partially oxidized organic matter (POOM) prevented minerals from excessive absorption of oxygen. The POOM allowed oxygen to be freed into the atmosphere, instead of being absorbed by minerals.

Furthermore, the researchers were able to identify the evolutionary history of monooxygenases, a key enzyme family able to generate POOM. The increase of this enzyme family has amplified the production of oxygen since then.

Great Oxidation Event

The Great Oxidation Event (GOE) has significantly detoxified Earth from harmful chemicals and elements from the onset of Earth's formation, according to a separate study published in the Proceedings of the National Academy of Sciences (PNAS) of the United States of America in 2020.

Also called the Great Oxygenation Event, the Oxygen Crisis, and the Oxygen Catastrophe; the GOE remodeled the global cycle of toxic particles-which ultimately led to a geological and climatic transformation of the atmosphere, oceans, and the environment as a whole.

The 2020 study showed the GOE has set up the necessary conditions for the emergency, evolution, and diversification of life. Until today, oxygen has remained a vital source for plants to produce food and for the human brain and other organs to function.

Oxygen Shortage

In spite of the abundance of oxygen from the oxygenation event, the growing human population and decreasing number of trees due to deforestation and illegal logging have contributed to a potential oxygen shortage in the future.

For instance, there have been cases of global oxygen shortages in the healthcare industry since the onset of the COVID-19 pandemic in March 2020, according to the WHO and the Relief Web humanitarian page of the UN Office for the Coordination of Humanitarian Affairs (OCHA).