SoylentNews

takyon writes:

A NASA study of fungi in a simulated Mars habitat found that fungal diversity increased and changed after humans were introduced, with certain fungi increasing or decreasing in presence over a period of 30 days. The results have implications for the cleaning and maintenance of space habitats to ensure the health of astronauts, and may lead to the screening of the mycobiomes of potential spacecraft/habitat occupants:

Three crews of students lived in an inflatable lunar/Mars analog habitat (ILMAH) for 30 days. The ILMAH was closed off from the outside world for the duration of their stay, except for an exchange of filtered air. Prior to habitation, the surfaces were cleaned with a bleach solution, and during the experiment, the surfaces were cleaned weekly with antibacterial wipes. Eight surfaces in the habitat were sampled four times: on day zero, day 13, day 20, and day 30.

By culturing the samples, the researchers uncovered a significant increase in fungal abundance between the collection time points. They also found that the culturable fungal population was higher for the lab area of the ILMAH than the others. In particular, they identified Cladosporium cladosporioides, Epicoccum nigrum, and Aspergillus tubingensis among the culturable fungi.

[...] When they examined the samples over time, they observed variations in abundance and noted that during human occupation of the ILMAH, the fungal diversity changed. For instance, levels of Pleosporaceae varied from 96 percent on day zero to 47 percent on day 20, and up to 70 percent on day 30. While Pleosporaceae decreased on day 20, levels of Davidiellaceae, Dothioraceae, Saccharomycetales, and Trichocomaceae increased, as compared to other time points.

Similarly, Epicoccum, Alternaria, Pleosporales, and Cryptococcus were highly abundant at day zero, but decreased in numbers by day 20 before increasing again by day 30.

They further noted that Alternaria, Cladosporium, and Epicoccum — all of which they uncovered in their study — are common household fungi. Though the researchers said that Cladosporium cladosporioides rarely causes infections, they said it could lead to asthmatic reactions in people with weakened immune systems, such as astronauts.

Also at EurekAlert and CNET.

Human presence impacts fungal diversity of inflated lunar/Mars analog habitat (open, DOI: 10.1186/s40168-017-0280-8) (DX)

Original Submission