New RNA Method Measures Viral Lysis of Marine Algae, a Key Driver of Ocean Carbon Cycling

Researchers have developed a method using cell-free ribosomal RNA to quantify how often marine algae are killed by viruses, a process called viral lysis. This lysis releases dissolved organic carbon that feeds the microbial loop, redirecting carbon away from the classic food web. The study, published in MicrobiologyOpen, tested the approach on two algae species and found it can track lysis rates with high sensitivity, offering a taxon-resolved tool for ocean carbon models. The method, called MoRS, compares rRNA in cellular and dissolved fractions of seawater. Controlled infection experiments showed that cell-free rRNA spikes sharply when viruses burst algal cells. The authors also built a degradation model using spike-in controls to correct for RNA decay. This could help estimate how much carbon is shunted into the microbial loop, a major uncertainty in climate and biogeochemical models. Limitations remain, such as variable ribosome content and non-viral lysis sources, but the approach provides a new way to read plankton mortality directly from seawater.