Ancient Microbes Produced Oxygen A Billion Years Earlier Than Thought

A researcher with Imperial College London in UK, Dr. Tanai Cardona did a study on molecular machines responsible for oxygenic photosynthesis and came to the conclusion that the process might have originated a billion years ago than previously thought. Photosynthesis is the basis of all life on Earth. There are two types of photosynthesis:

• Oxygenic photosynthesis: Here, plants and other beings use light energy, carbon dioxide and water to convert it into carbohydrate and oxygen.
• Anoxygenic photosynthesis: This type of photosynthesis does not produce oxygen as a byproduct and uses compounds such as hydrogen sulphide or minerals such as iron or arsenic to complete the conversion.

Dr. Cardona wanted to discover when oxygenic photosynthesis originated on Earth. But, instead of trying to find it out through ancient rocks, he dug deep inside the molecular machines that carried out photosynthesis. These complex enzymes are called photosystems. Both oxygenic and anoxygenic photosynthesis use an enzyme called Photosystem. In both types of photosynthesis, the core of the enzyme is different. By making out how earlier these two genes evolved to be different can conclude when oxidative photosynthesis first occurred.

After his research, he concluded that the genes may have occurred more than 3.4 billion years ago. This is much before when cyanobacteria (first microbes that produced oxygen) actually occurred. This means that there might have been ancient microbes that could produce oxygen earlier than thought.

By: Neha Maheshwari

Content: http://www.sci-news.com/biology/oxygenic-photosynthesis-05794.html