Microbes Afloat

BACTERIA AND THE VIRUSES that infect them are perpetually at war. Their deadly clashes push both kinds of microbes to evolve new traits that meet the challenges of every environment they inhabit, from the human digestive tract to the seafloor’s hydrothermal vents— and even the harsh conditions of space.

-  K. R. Callaway

To see how microgravity changes certain microbes, researchers sent bacteria-infecting viruses called bacteriophages to the International Space Station, and they found that the viruses adapted in ways that made them even more effective at infection.

In the experiment, detailed in PLOS Biology, the team incubated specimens of common lab bacteriophage T7 alongside its foe, Escherichia coli bacteria, for varying durations. They ran the same experiment on Earth and in space; the terrestrially reared viruses infected bacteria within two to four hours, but those in space took more than four hours to breach bacteria’s defenses. The infection took longer in orbit because microgravity is an unfamiliar stressor to which both microbes must adapt, the researchers suggest.