Evaluation of toxicity of lunar and Martian regolith on skin microbiome-relevant bacteria
Abstract
The exploration and potential colonization of celestial bodies such as the Moon and Mars present unique challenges, one of which is understanding the toxicity of lunar and Martian regolith to the colonizers and to their microbiomes. Our study assessed the toxicity of regolith simulants on Escherichia coli and Staphylococcus epidermidis, commonly associated with human skin microbiome. For this purpose, various concentrations of simulants were added to E. coli and S. epidermidis cultures before incubation at 30 °C and 37 °C, respectively, with constant agitation at 200 rpm. Changes in the growth rates, viability, and biofilm development of our models were monitored over different exposure times using optical density, colony-forming units and crystal violet assays. Our results suggest dose-dependent effects of the simulants on bacterial growth and viability. At lower concentrations of simulants, only minor impacts on the growth of both species is expected. Whereas with a higher concentration, a reduction in growth will occur, indicating increased toxicity. Overall, our study highlights the potential toxicity of lunar and Martian regolith on bacterial species and the importance of understanding its impact on microbial life for future space exploration and planetary protection protocols.
Evaluation of toxicity of lunar and Martian regolith on skin microbiome-relevant bacteria
The exploration and potential colonization of celestial bodies such as the Moon and Mars present unique challenges, one of which is understanding the toxicity of lunar and Martian regolith to the colonizers and to their microbiomes. Our study assessed the toxicity of regolith simulants on Escherichia coli and Staphylococcus epidermidis, commonly associated with human skin microbiome. For this purpose, various concentrations of simulants were added to E. coli and S. epidermidis cultures before incubation at 30 °C and 37 °C, respectively, with constant agitation at 200 rpm. Changes in the growth rates, viability, and biofilm development of our models were monitored over different exposure times using optical density, colony-forming units and crystal violet assays. Our results suggest dose-dependent effects of the simulants on bacterial growth and viability. At lower concentrations of simulants, only minor impacts on the growth of both species is expected. Whereas with a higher concentration, a reduction in growth will occur, indicating increased toxicity. Overall, our study highlights the potential toxicity of lunar and Martian regolith on bacterial species and the importance of understanding its impact on microbial life for future space exploration and planetary protection protocols.