Examining viruses that can help “increase” carbon capture in the sea

Armed with a catalog of hundreds of thousands of species of DNA and RNA viruses found in the world’s oceans, scientists are now focusing on viruses most likely to combat climate change by helping trap carbon dioxide. carbon in seawater or, using similar techniques, on different viruses that could prevent the escape of methane from thawing Arctic soils.

By combining genomic sequencing data with artificial intelligence analysis, researchers have identified viruses present in the oceans and evaluated their genomes to discover that they “steal” genes from other microbes or cells that process the carbon in the sea. Mapping genes for microbial metabolism, including those for underwater carbon metabolism, has revealed 340 known metabolic pathways in the world’s oceans. Of these, 128 were also found in the genome of ocean viruses.

“I was shocked that this number was so high,” said Matthew Sullivan, professor of microbiology and director of the Center of Microbiome Science at Ohio State University.

Having exploited this massive trove of data through advances in computing, the team has now revealed which viruses play a role in carbon metabolism and is using this information in recently developed community metabolic models to help predict how carbon utilization viruses to modify the ocean microbiome for better carbon. the capture would look like.

“The modeling is looking at how viruses can increase or decrease microbial activity in the system,” Sullivan said. “Community metabolic modeling gives me the data of my dream: which viruses target the most important metabolic pathways, and this is important because it means they are good levers to pull on.”

Sullivan presented his research today at the annual meeting of the American Association for the Advancement of Science in Denver.

Sullivan was the virus coordinator for the Tara Oceans Consortium, a three-year global study of the impact of climate change on the world’s oceans and the source of 35,000 water samples containing the microbial bounty. His lab focuses on phages, viruses that infect bacteria, and their potential to be scaled up in an engineering framework to manipulate marine microbes to convert carbon into the heaviest organic form that will sink to the bottom of the ocean. the ocean.

“The oceans absorb carbon, which protects us from climate change. CO₂ is absorbed as a gas and its conversion to organic carbon is dictated by the microbes,” Sullivan said. “What we’re seeing now is that the viruses are targeting the most important reactions in the metabolisms of these microbial communities. This means we can start investigating which viruses could be used to convert carbon into whatever we want.

“In other words, can we strengthen this huge ocean buffer to make it a carbon sink to buy time against climate change, instead of that carbon being released into the atmosphere to accelerate it?”

In 2016, the Tara team determined that carbon sinking in the ocean was linked to the presence of viruses. Viruses are thought to help absorb carbon when infected carbon-processing cells clump together into larger, sticky aggregates that sink to the ocean floor. Researchers have developed AI-based analyzes to identify thousands of viruses, few of which are “VIP” viruses, to grow in the laboratory and use as model systems for ocean geoengineering.

This new community-based metabolic modeling, developed by Professor Damien Eveillard of the Tara Oceans Consortium, helps them understand what the unintended consequences of such an approach could be. Sullivan’s lab takes these oceanic lessons and applies them to using viruses to modify microbiomes in human settings to facilitate recovery from spinal cord injury, improve outcomes for infants born to HIV-positive mothers , fight burn infection, and much more.

“The conversation we’re having is, ‘How transferable is this?'” said Sullivan, also a professor of civil, environmental and geodetic engineering. “The overall goal is to engineer microbiomes for what we think we’re doing something useful.”

He also reported on early efforts to use phages as geoengineering tools in an entirely different ecosystem: the permafrost of northern Sweden, where microbes modify the climate and respond to climate change as the ground freezes. thaws.

Virginia Rich, associate professor of microbiology at Ohio State, is co-director of the EMERGE Biology Integration Institute based at Ohio State, which organizes microbiome science at the Swedish site. Rich also co-led previous research that identified a lineage of single-celled organisms found in thawing permafrost soil as a significant producer of methane, a potent greenhouse gas.

Rich co-hosted the AAAS session with Ruth Varner of the University of New Hampshire, who co-directs the EMERGE Institute, which focuses on better understanding how microbiomes respond to thawing permafrost and the climate interactions that cause it. result.

Sullivan’s talk was titled “From Ecosystem Biology to Managing Microbiomes with Viruses” and was presented during the session titled “Microbiome-Focused Ecosystem Management: Small Players, Big Roles.”