Station Science Top News: May 18, 2023
Solidification experiments in microgravity revealed that invasion by cells formed in one area or grain into another resulted in highly convoluted shapes. Solidification is part of processes such as welding and additive manufacturing, and the patterns or grains that form heavily influence the end material’s performance. This discovery changes the traditional concept of grains as distinct regions.
These experiments used the International Space Station DECLIC facility, which provides the consistent conditions of microgravity and allows imaging of the solidification of transparent organic compounds. Such work helps scientists understand how boundaries in solidification affect the behavior of biological systems and the properties of structural materials.
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E. coli bacteria isolated from astronauts and cultured during spaceflight showed increased antibiotic resistance (AR) compared to those cultured preflight. These results could contribute to better management of AR, which can cause treatment complications and failure in astronauts.
The Plasmid investigation examined microgravity’s effect on bacteria plasmids – DNA molecules that are physically separate from chromosomal DNA and replicate independently. Scientists suspect that formation of dangerous bacterial strains is related to the recombining of plasmids. This study showed that most bacteria in space had two AR determinants or genes, requiring treatment by at least three different antibiotics.
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An examination of biofilms aboard the space station shows that Nanograss was the most efficient material tested at reducing biofilm formation in microgravity and on Earth. Biofilm formation can cause equipment malfunction and human illness. Additional study is needed to determine the potential of Nanograss as an anti-microbial surface for future spacecraft equipment.
Space Biofilms analyzed a fungal species grown in space on seven different materials: stainless steel, aluminum alloy, titanium alloy, carbon fiber, quartz, silicone, and Nanograss. Nanograss is a textured silicon wafer material developed by MIT. Cell-to-surface and cell-to-cell adhesion is an important part of biofilm formation. The roughness and charge of Nanograss may limit biofilm growth by limiting adhesion.
