The Mariana Trench, Earth’s deepest point, descends to a staggering depth of nearly 11,000 meters on the floor of the Pacific Ocean. In this dark and frigid environment, life persists, and as marine virologist Min Wang, Ph.D., of the Ocean University of China in Qingdao, points out, “wherever there’s life, you can bet there are regulators at work.” Here, the regulators are Ocean virus. In a recent publication in Microbiology Spectrum, Dr. Wang and an international team of researchers have unveiled the discovery of a novel virus found in sediment retrieved from a depth of 8,900 meters.
This virus belongs to the category of bacteriophages, which are viruses that infect and replicate within bacteria. Bacteriophages are believed to be the most abundant life forms on our planet. Dr. Wang emphasizes, “To our best knowledge, this is the deepest known isolated phage in the global ocean.”
OCEAN VIRUS; TARGETS BACTERIA
The newly identified phage targets bacteria within the phylum Halomonas, commonly found in deep-sea sediments and around hydrothermal vents. Hydrothermal vents are vent-like openings on the ocean floor that release streams of superheated water. Dr. Wang and the team’s genetic analysis of the virus’s material reveal the existence of a previously unknown viral family in the deep ocean. This discovery also sheds new light on the diversity, evolution, and genomic characteristics of deep-sea phages and their interactions with their bacterial hosts.
In previous research, the team employed metagenomic analysis to study viruses that infect bacteria within the Oceanospirallales order, which includes Halomonas. For this latest study, Dr. Wang’s group explored viruses within bacterial strains collected and isolated by a team led by marine virologist Yu-Zhong Zhang, Ph.D., also at the Ocean University of China, Qingdao. Dr. Zhang’s research focuses on microbial life in extreme environments, including the Polar Regions and the Mariana Trench.
OCAEN VIRUS; WIDE DISTRIBUTION
The genomic analysis of the newfound virus, identified as vB_HmeY_H4907, indicates its wide distribution in the ocean and a similar structure to its host. Dr. Wang suggests that this study poses new questions and research avenues, particularly concerning the survival strategies of viruses in harsh, secluded environments and their co-evolution with their host bacteria. Notably, the new virus is lysogenic, meaning it invades and replicates within its host without typically killing the bacterial cell. As the cell divides, the viral genetic material is also duplicated and passed on.
In future investigations, Dr. Wang’s team plans to delve into the molecular mechanisms that govern interactions between deep-sea viruses and their hosts. They are also actively searching for other novel viruses in extreme environments, contributing to our broader understanding of the virosphere. As Dr. Wang aptly states, “Extreme environments offer optimal prospects for unearthing novel viruses.”
