[Journal of Virology]. Biogeochemical models have become critical for answering questions about the habitability of ocean worlds, especially that of early Earth.
However, when extended to icy moons, experimental biogeochemical systems become especially challenging. Due to less constrained physicochemical parameters extrapolated from former flybys, the most comprehensive approaches could combine experimental and computational models of proposed ocean conditions with microbes present.
This minireview makes the case for needing to also include viral/phage interactions with microbial models as a mechanism for maintaining biogeochemical cycling.
Map with example locations of Earth analog ocean vent ecosystems with extremophiles that thrive in alkaline (purple) and acidic (orange) conditions. The figure was created with BioRender.com. — Journal of Virology
The viral shunt, or the release and recycling of organic/inorganic matter in aquatic ocean systems via the viral lysis of bacteria and archaea, has proven to be a critical source of carbon/sulfur/iron cycling throughout Earth’s oceans.
Nonetheless, the viral shunt remains understudied in the realm of other ocean world astrobiology and habitability studies but may provide a mechanism for detection of organics by future missions. The current knowledge of physicochemical conditions on three ocean worlds (Enceladus, Europa, and Titan) is briefly summarized in this work to contextualize examples of Earth-based integrated archaeal viruses (Pyrobaculum filamentous virus, Sulfolobus turreted icosahedral virus, and Methanosarcina spherical virus) that may be suitable for habitability studies for virus-integrated biogeochemical ocean world models.
Proposed geomicrobiological models for Enceladus, Europa, and Titan. Archaeal (Pyrobaculum, Sulfolobus, Methanosarcinales, and ANMEs) and viral models (PFV, STIV, and MetSV) for each ocean world are shown alongside their potential biogeochemical cycles, with an emphasis on C/H/S sources and sinks from tidal heating, viral shunt, and hydrothermal emissions. The figure was created with BioRender.com. — Journal of Virology
- Virus-integrated laboratory models for habitability studies of Enceladus, Europa, and Titan, Journal of Virology via PubMed
- Virus-integrated laboratory models for habitability studies of Enceladus, Europa, and Titan, Journal of Virology (open access)
Astrobiology,
