Location and surface materials drive differences in microbial communities in the confined HI-SEAS IV habitat

Abstract

Humans regularly interact with microbiota on abiotic surfaces promoting its growth or inhibition, which can be well characterized in confined spaces. The Hawaii Space Exploration Analog and Simulation (HI-SEAS) mission IV study examined the microbiome of a confined habitat that simulates the environment in which astronauts will live when sent out on Mars and Moon exploration missions. Indeed, differences in microbial diversity and composition was previously identified between different surface materials, but the effects of surface materials and location on bacterial taxonomic profile and abundances had yet to be explored. Using the collected data from the HI-SEAS IV environment, results showed that microbial taxa on plastic surfaces in three different locations within the habitat had highly conserved taxonomic profiles at the genus-level yet contained significantly different beta diversities and differential abundances. The few unique genera observed from each location is presumed to be due to the functional differences of each area. Notably, both the living room and bedroom compared to the bathroom had significantly higher levels of Methylophilus, which are facultative methanol-utilizing bacteria, possibly due to use of disinfecting wipes and hand sanitizers containing toxic methanol contaminants. Bacteria associated with the human microbiome generally dominated the bathroom and bedroom, with many significant genera being associated with the female reproductive tract. In conclusion, considerations should be given to the surface materials and locations within a confined environment when monitoring bacterial communities in enclosed environments.