Graphic shows chemosynthesis route to edible protein.
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SCIENCE

Wonder food made by chemosynthesis

By Duncan Mil

January 14, 2020 - A source of protein created by bacteria from carbon dioxide, water and renewable energy is more efficient than photosynthesis used by plants.

Photosynthesis is the process which plants, algae and some bacteria use to harness energy from sunlight and turn inorganic carbon, nitrogen and sulphate ions into digestible carbohydrates, proteins and fats.

However, in the blackness of the deep ocean, hydrogen-oxidizing bacteria that live around hydrothermal vents are denied light energy. Here, plumes of mineral-laden fluid flow from ocean-bed vents at temperatures as high as 400 degrees Celsius. These bacteria use a process known as chemosynthesis -- a process analogous to photosynthesis.

In the 1960s, researchers John Foster and John Litchfield worked on a NASA project for space life-support systems at Battelle Memorial Institute in Columbus, Ohio. Foster and Litchfield used the hydrogen-fixing bacterium Ralstonia eutropha to produce a food protein by chemosynthesis, with carbon dioxide exhaled by astronauts and hydrogen as carbon and energy sources, respectively. Animal feeding studies revealed good growth with rats; however, problems in feeding primates indicated a possible presence of a toxin.

Now, Finnish startup Solar Foods has come up with a way to produce a protein-rich food called Solein using chemosynthesis. Solein is made by electrolysis of water to release bubbles of carbon dioxide and hydrogen. Bacteria feed on the carbon dioxide and hydrogen and produce the Solein, which is then dried to make a powder. The dried Solein has a protein content of 50 per cent and looks and tastes similar to wheat flour.

PUBLISHED: 14/01/2020; STORY: Graphic News
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