Within the complex hierarchy of marine ecosystems, giant viruses are now being recognized as novel drivers of both ecological balance and carbon cycling. A new study published in Nature npj Viruses, by researchers at the University of Miami’s Rosenstiel School, broadens our understanding of these viral giants, revealing 230 new genomes and hundreds of previously unidentified proteins.
The study’s lead author, Benjamin Minch, used a novel genome-mining tool called BEREN (Bioinformatic tool for Eukaryotic virus Recovery from Environmental metageNomes) to extract viral sequences from marine metagenomic datasets collected from nine global ocean surveys.
These giant viruses were found to target vital components of the microbial food web, including algae and flagellates. When infected, these microbial hosts can effectively be reprogrammed. In some cases, this reprogramming can enhance the metabolic capacity of their hosts, encoding genes for central carbon metabolism and ATP generation.
But among the most surprising of the research team’s findings were nine new proteins tied to photosynthesis, suggesting these viruses are capable of hijacking their host’s ability to process energy. Other proteins were found to encode for enzymes once thought exclusive to cellular life, challenging the boundaries of what we have previously understood about the role of viruses in the global food chain.
“By better understanding the diversity and role of giant viruses in the ocean and how they interact with algae and other ocean microbes, we can predict and possibly manage harmful algal blooms, which are human health hazards in Florida as well as all over the world,” said Mohammad Moniruzzaman, a co-author of the study and an assistant professor in the Department of Marine Biology and Ecology. “Giant viruses are often the main cause of death for many phytoplankton, which serve as the base of the food web supporting ocean ecosystems and food sources. The novel functions found in giant viruses could have biotechnological potential, as some of these functions might represent novel enzymes.”
The findings show that giant viruses aren’t just passive players within the ocean’s ecosystem. They are dynamic engineers influencing marine biodiversity, microbial evolution, and even climate-regulating processes related to carbon cycling.
The metabolic and photosynthetic genes found in some viruses suggest they may augment their hosts’ ability to replicate, effectively rewiring microscopic life and impacting global energy flow.
Research into giant ocean viruses is a rapidly evolving field. The effort to understand their diversity and ecological roles will provide a more complete understanding of ocean health and the impact on global carbon cycling.
The complete dataset, genome annotations, and BEREN software are available for public use.
This new study was published in the journal Nature njp Viruses.
Source: University of Miami News
