The discovery of a unique mechanism of photosynthesis adopted by a type of desert bacteria

Plant photosynthesis has changed the landscape on Earth. In this process, which depends on sunlight, plants produce oxygen and power our ecosystem.

A recent study published in the journal Science Advances on February 16 reported that a type of bacteria has developed a unique ability that enables it to carry out the process of photosynthesis, and the study indicated that the molecular mechanisms responsible for the process of photosynthesis in these bacteria. It was unlike any of its previously known counterparts.

According to the report , published by Science Alert, Michal Koplesic, assistant professor at the Institute of Microbiology of the Czech Academy of Sciences and lead of the study, says that "the structure [of the complex cellular machinery responsible for metabolism] The photosynthesis in these bacteria] is absolutely amazing. It's really a natural masterpiece."

Koplesic describes this discovered structure as "not only structurally stable, but also showing high light absorption efficiency."

Horizontal gene transfer

It is noteworthy that the bacteria were discovered 8 years ago in Lake Tian E Hu in the Gobi desert of East Asia.

These bacteria belong to a rare species known as "Gemmatimonas phototrophica" that contains the bacterial pigment chlorophyll (Bacteriochlorophyll). Genetic analysis of these bacteria has shown that they adopt an ancient form of photosynthesis.

Although we know a lot about bacteria that perform photosynthesis, what happens inside Gimatimonas phototrophica is unique.

Apparently, these bacteria have retained - during their evolutionary history - a whole set of genes related to the process of photosynthesis that they derived from types of proteobacteria or ancient "Proteobacteria", which are a group of bacteria completely different from them.

Bacteria are characterized by their ability to pass their genes laterally (also called horizontal transfer) to other bacteria that are not their offspring, which is different from other organisms that pass their genetic genes vertically to their offspring. Thus, the superior ability to pass the genes in this way enabled the bacteria "Gematomonas phototrophica" to acquire the genes that helped it to carry out the process of photosynthesis.

Unique structural structure

The protein complex, which is responsible for absorbing sunlight, consists of a central part, an inner ring that absorbs sunlight (seen before in other bacteria) and a completely new outer ring. Hence, these three components make this discovered protein complex the largest photosynthesis complex discovered to date.

The new outer rings absorb sunlight, as these rings increase the spectral range of the absorbed sunlight to include wavelengths at 800 and 816 nanometers. The inner ring absorbs the spectrum of the sun at a wavelength of 868 nanometers, and then these rings pass the photons of the captured radiation to the core of the protein complex, where the reaction center is located.

Photosynthesis takes place in this central core where the chromophores are located. Absorbed sunlight stimulates the transmission of electrons for those chromosomes through a series of reactions that use carbon dioxide and produce sugars.

Interaction Center

It also enters some of the sun's rays in the formation of energy that binds sugar molecules together, which humans and other living organisms feed on. And when our biological systems break these bonds, they extract energy from those sugar molecules.

This reaction center is similar to that of the "proteobacteria", and it contains the same chromosomes as the purple bacteria that absorb sunlight, but the structure of this reaction center is unique and different from other known reaction centers.

Although this unique structure requires more energy than other more common species, its strong stability may compensate for this, which may represent an evolutionary advantage for this type of bacteria.