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From the Abyss: New Virus Discovered in Earth’s Deepest Ocean Trench

Researchers discovered a new bacteriophage from the Mariana Trench, specifically from sediments at a depth of 8,900 meters. This discovery points to a previously unknown viral family in the deep ocean and offers insights into the genomic characteristics and evolution of deep-sea viruses.

The Mariana Trench, the deepest place on Earth, descends almost 11,000 meters (36,000 feet) at its lowest point on the floor of the Pacific Ocean. Even in this profound and chilly abyss, life persists. “wherever there’s life, you can bet there are regulators at work,” said marine virologist Min Wang, Ph.D., at the Ocean University of China, in Qingdao. “Viruses, in this case.”

In a study recently published in the journal Microbiology Spectrum, Wang and an international group of researchers report the discovery of a new virusA virus is a tiny infectious agent that is not considered a living organism. It consists of genetic material, either DNA or RNA, that is surrounded by a protein coat called a capsid. Some viruses also have an outer envelope made up of lipids that surrounds the capsid. Viruses can infect a wide range of organisms, including humans, animals, plants, and even bacteria. They rely on host cells to replicate and multiply, hijacking the cell's machinery to make copies of themselves. This process can cause damage to the host cell and lead to various diseases, ranging from mild to severe. Common viral infections include the flu, colds, HIV, and COVID-19. Vaccines and antiviral medications can help prevent and treat viral infections.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>virus isolated from sediment brought up from a depth of 8,900 meters (29,200 feet). The virus is a bacteriophage, or a virus that infects and replicates inside bacteria, and bacteriophages are believed to be the most abundant life forms on the planet. “To our best knowledge, this is the deepest known isolated phage in the global ocean,” said Wang.

The newly found phage infects bacteria in the phylum Halomonas, which are often found in sediments from the deep seas and from hydrothermal vents, geyser-like openings on the seafloor that release streams of heated water. Wang said the group’s analysis of the viral genetic material points to the existence of a previously unknown viral family in the deep ocean, as well as new insights into the diversity, evolution, and genomic features of deep-sea phages and phage-host interactions.

In previous work, the researchers have used metagenomic analysis to study viruses that infect bacteria in the order Oceanospirallales, which includes Halomonas. For the new study, Wang’s team looked for viruses in bacterial strains collected and isolated by a team led by marine virologist Yu-Zhong Zhang, Ph.D., also at the Ocean University of China, in Qingdao. Zhang’s research explores microbial life in extreme environments, including polar regions and the Mariana Trench.

The genomic analysis of the new virus, identified as vB_HmeY_H4907, suggests that it is distributed widely in the ocean and has a similar structure to its host. Wang said the study points to new questions and research areas focused on the survival strategies of viruses in harsh, secluded environments—and how they co-evolve with their hosts. The new virus is lysogenic, which means it invades and replicates inside its host, but usually without killing the bacterial cell. As the cell divides, the viral genetic material is also copied and passed on.

In future studies, Wang said, the group plans to investigate the molecular machinery that drives interactions between deep-sea viruses and their hosts. They’re also searching for other new viruses in extreme places, “which would contribute to broadening our comprehension of the virosphere,” Wang said. “Extreme environments offer optimal prospects for unearthing novel viruses.”

Reference: “Identification and genomic analysis of temperate Halomonas bacteriophage vB_HmeY_H4907 from the surface sediment of the Mariana Trench at a depth of 8,900 m” by Yue Su, Wenjing Zhang, Yantao Liang, Hongmin Wang, Yundan Liu, Kaiyang Zheng, Ziqi Liu, Hao Yu, Linyi Ren, Hongbing Shao, Yeong Yik Sung, Wen Jye Mok, Li Lian Wong, Yu-Zhong Zhang, Andrew McMinn and Min Wang, 20 September 2023, Microbiology Spectrum.
DOI: 10.1128/spectrum.01912-23

Source: SciTechDaily