New Delhi: Ocean viruses are not passive participants in global nutrient cycles; instead, they are gene thieves that plague marine microbes, according to research conducted by Ohio State University. These viruses that target microbes involved in the recycling of nutrients contain genes that affect about a third of ocean metabolism. These microbes and their viruses play a crucial role in the functioning of the ocean, particularly in the processes of carbon absorption and oxygen production that are vital to regulating the climate and composition of the planet.
The work is based on a finding made two decades ago that viruses can transfer genes with photosynthetic cells. This new research, published in Microbiome, compiles data from more than 100 studies, which has generated a repository of approximately 23,000 genes, of which more than 7,000 are newly found auxiliary metabolic genes (AMGs). These AMGs are segments that viruses steal from host microbes to instruct the host metabolism for the advantage of the virus. According to the studies, 20% of ocean viruses contain at least one AMG; which in turn impacts microbial nutrient processes.
Viral Impact on Ocean Metabolism
A group headed by microbiologist Funing Tian and her co-author James Wainaina first identified 340 metabolic pathways used by ocean microbes to process nutrients. Surprisingly, 128 of such pathways 37% are interfered by viral AMGs, suggesting that viruses significantly contribute to re-shaping these microbes to modify the nutrient dynamics in the ocean. The research applied computational methods and involved 7.6 terabytes of data from the Tara Oceans metagenomic project to find viral AMGs and their specific host activities.
Paving the Way for Climate Modeling and the Next Steps
These findings can provide a starting point for how to work viruses into the current ocean models for prediction, said the study’s senior author Matthew Sullivan, a professor of microbiology at Ohio State University and director of the Center for Microbiome Science. Until now, many models did not include viruses at all, and many did not involve microbes in any way. Sullivan explained that with these discoveries, scientists can model how viral processes impact nutrient cycling and be able to make more reliable predictions of the ocean’s reaction to climate change.
This research is carried out under the support of various scientific foundations and the Ohio Supercomputer Center; the study is worldwide. After joining the University of Chicago, Tian and Wainaina of Woods Hole Oceanographic Institution along with the international team broadened the understanding of how viruses form the nutrient cycling and created the basis for further microbiome engineering and climate research.
