Photosynthetic microorganisms depend on sunlight to survive. Indeed, it is necessary for them to produce the energy that their body needs. A new article appeared in the PNAS journal today reveals the secret of these microscopic living beings. Having been conducted by researchers fromUniversity of Chicago andWashington University at St. Louis, this new study suggests that photosynthetic bacteria exploit quantum mechanics to avoid dying.
“Before this study, the scientific community had discovered quantum signatures generated in biological systems and asked themselves the following question: were these fingerprints simply a consequence of the fact that biology is built from molecules or did they have a purpose? ? “said Greg Engel of the University of Chicago and lead author of the study, cited by Science Alert.
Chlorobium tepidum, an amazing bacterium
As part of their work, the scientists analyzed a microorganism called Chlorobium. It is a phototrophic anaerobic bacteria which is also thermophilic. In other words, chlorobium tepidum need light to stay alive. Their photosynthetic system is, however, extremely vulnerable to oxygen.
Which is useful for us to release the energy brought by the glucose inside our cells can therefore destroy the mechanism of transformation of light into chemicals inside photosynthetic microbes.
A quantum effect to transfer energy
In order to avoid such a disaster, chlorobium tepidum has developed means allowing it to reduce damage from exposure to oxygen. The means in question are to direct energy to where the body is least at risk.
In order to study this mechanism, the researchers followed the movement of energy through a photosynthetic protein under different conditions, namely, with and without oxygen. This allowed them to discover that the bacteria used a quantum mechanical effect dubbed vibronic mixture to transfer energy between two different paths, depending on the presence or absence of oxygen.
A major discovery
In the absence of oxygen, the microorganism makes use of vibronic interaction by bringing the energy gap between two electronic states closer together in a mixture of molecules and proteins called FMO complex (Fenna-Matthews-Olson). This shifts energy through the “normal” pathway to the photosynthetic reaction center, which is full of chlorophylle.
And when there is oxygen, the bacteria adapts their body to direct energy to a less direct path where it can be attenuated. According to the researchers, this finding is of great importance insofar as it proves that certain living beings use quantum effects to increase their life expectancy. They also believe that this mechanism does not only concern chlorobium tepidum.
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