Scientists have made a fascinating discovery about the abundance of viruses on Earth, highlighting that their numbers far exceed the stars in the universe. Shockingly, for each star, there are at least 100 million viruses on our planet. Among these viruses, bacteriophages are the most common type, infecting and affecting bacteria. Microbiologists suggest that bacteriophages are the most prevalent life forms on our planet.

These resilient viruses have been found in some of the most extreme environments, from acidic hot springs to salty lakes, deserts, mountains and even arctic ice. Recently, a group of international researchers made an extraordinary find: a new bacteriophage in a sediment sample collected from the Mariana Trench, the deepest point on Earth, located at a depth of 8,900 meters (29,200 feet).

Min Wang, a professor at the Ocean University of China and one of the researchers, remarked, "To our best knowledge, this is the deepest known isolated phage in the global ocean."

This newly discovered bacteriophage has been named vB_HmeY_H4907. It targets halophilic bacteria, which are bacteria that thrive in environments with high salt concentrations, typically found in deep-sea hydrothermal vents.

Notably, this isn't the first time that scientists have encountered a bacteriophage in the Mariana Trench. In 2022, another team isolated a virus called HMP1 from the hadal region of the trench, which spans depths ranging from 6,000 meters to 11,000 meters.

What sets vB_HmeY_H4907 apart is its potential indication of a previously unknown viral family in the deep ocean. This discovery opens up new perspectives on the evolution, diversity, and genomic characteristics of deep-sea bacteriophages and their hosts.

The researchers isolated vB_HmeY_H4907 from a sediment sample containing halophilic bacterial strains. Genomic analysis revealed that this phage is lysogenic, meaning that, unlike many other phage species, it doesn't kill its host. Instead, it infects, replicates, and continues to pass on to the next generation.

This study also suggests that the bacteriophage is widespread throughout the ocean and bears a striking resemblance to Halomonas bacteria. This raises intriguing questions about the co-evolution of this virus and its host in the depths of the ocean.

Scientists plan to further investigate the genetic characteristics of vB_HmeY_H4907, aiming to gain a deeper understanding of how these microorganisms interact with their hosts and survive in such extreme environments.

Min Wang summarizes their work by noting, "Wherever there's life, you can bet there are regulators at work," such as these viruses in this particular case.

The study detailing this discovery has been published in the journal Microbiology Spectrum.