NEXT time you take in a lungful of oxygen, consider this: it was made possible in part by ocean viruses.
The viruses, which infect single-celled algae called cyanobacteria, are hyperefficient photosynthesisers thanks to a unique set of genes.
Previous work had shown that cyanophage viruses have some photosynthesis genes, apparently used to keep the host cyanobacteria on life support during the infection, which otherwise knocks out the cells鈥� basic functions.
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Now from the Technion-Israel Institute of Technology in Haifa says that the cyanophages鈥� photosynthetic proficiency doesn鈥檛 stop there. While screening DNA sequences in water samples collected during Craig Venter鈥檚 , his team discovered seven more photosynthesis genes coding for a complex of proteins collectively named photosystem I. They believe the viral complex has a unique shape that makes cyanophage photosynthesis hyperefficient.
鈥淭he viral complex has a unique shape that makes photosynthesis hyperefficient鈥�
In normal photosynthesis, photosystem I grabs electrons from proteins higher up in the photosynthesis chain reaction. The team believe the viral photosystem I genes allow the cyanophages to not only take electrons from the proteins involved in photosythesis but also from other algal proteins.
鈥淲e suspect that when these phages enter the cell, they start to replace [the cell鈥檚] photosystem,鈥� says B茅j脿. 鈥淏y grabbing electrons from all sources available at the time, they get more energy out of photosynthesis.鈥�
of the University of Delaware in Newark says the discovery suggests these viruses may play a role in global oxygen production. 鈥淭heir hosts produce half the world鈥檚 oxygen and roughly 10 per cent of these cells are infected by cyanophages,鈥� he says. 鈥淪o it is possible that as much as 5 per cent of the world鈥檚 oxygen production results from cyanophage infected cells.鈥�
