"Intra-specific differences in bacterial responses to modeled reduced gravity" by Paul W. Baker and Laura G. Leff describes differences in bacterial responses to reduced gravity and how for some species, bacteria from the International Space Station (ISS), potentially are adapted to the unique environmental conditions of that system.
As bacteria are important residents in water systems, including those of space stations, examination of responses to conditions like microgravity may offer significant insight into the factors that influence bacterial distribution. In this study, water system bacterial isolates from the ISS were compared to other isolates from corresponding type strains of the same species. Reduced gravity was modeled using clinorotation. The findings suggest that conditions on the ISS might have favoured bacteria that were able to thrive under the unusual environmental conditions of this habitat. Responses to reduced gravity, coupled with impacts of other features (such as radiation resistance and the ability to persist under very low nutrient conditions), may contribute to the success of these water system bacteria.