Viral nutrition: new study reveals microbes nourished by consuming viruses

Researchers at the University of Nebraska-Lincoln have reported that a particular genus of plankton, namely Halteria, can ‘grow and divide given only viruses to eat’. This could be significant for the marine food chain 

John P. DeLong, James L. Van, Zeina Al-Ameeli, Irina V. Agarkova and David D. Dunigan, ‘The consumption of viruses returns energy to food chains’, Proceedings of the National Academy of Sciences, December 27, 2022. https://doi.org/10.1073/pnas.221500012

At various peaks of the COVID-19 pandemic, viruses have had a reputation as destroyers of public health systems and human lives. They have a peculiar biology — while inert outside a living body , but inside, they hijack the cellular machinery to feed, replicate and spread. This association with disease and death has come to define their form in the public imagination, redeemed not even by the fact that there are other microbes that destroy viruses. But a new study, published on December 27 by researchers at the University of Nebraska-Lincoln, offers to upend this.

The authors of the study have reported that a particular genus of plankton can consume viruses as well as “grow and divide given only viruses to eat”. We already know of other cells that can ‘consume’ viruses in an effort to destroy them — such as the macrophage cells of the human immune system.

The difference lies in being able to ‘eat’ viruses to fulfil one’s biological imperatives.

Plankton of the genus Halteria, they claim to have found, can each consume 10,000 to a million virus particles a day, increase their population using the metabolised energy, and provide more food for the zooplanktons that consume the Halteria. This could be significant for the marine food chain.

Plankton are microscopic organisms that can only move with a current. They don’t have any facilities to actively propel themselves. Halteria plankton are ciliates, meaning they have hair-like structures called cilia on their surface. Sometimes they can beat some of these cilia to jump short distances, but not often as it they can’t do this often because it requires too much energy.

What do plankton do in the food chain?