A novel large-area surface sampling method developed by NASA, using the Concentrating Pipette™, in use for nearly a decade to monitor the microbiome of the Space Station and NASA spacecraft manufacturing cleanrooms. This method has led to the discovery of at least three bacterial strains previously unknown to science. This summary represents just one of over 20 peer-reviewed papers utilizing this sampling technique.
Background
The International Space Station (ISS) hosts microorganisms originating from life support systems, cargo, and crew, all exposed to unique conditions such as microgravity. Traditional microbial monitoring of spacecraft and space stations has relied on culture methods, but many microbes cannot be cultured this way. To better understand the true number and diversity of microbes on the ISS, surface samples were analyzed using qPCR and sequencing methods.
Method
9” X 9” polyester wipes (Texwipe) were soaked in 15 mL of sterile molecular grade water and each was transferred to a sterile zip lock bag for future sampling.
Astronauts onboard the ISS performed the surface sampling at eight pre-defined locations during three flight missions spanning 14 months and the wipes were analyzed upon return to Earth.
Each used wipe was transferred to a 500 mL bottle containing 200 mL of sterile phosphate-buffered saline and shaken for 2 min followed by fast and easy concentration with a Concentrating Pipette using a 0.2 µm filter tip. The concentrates were assayed by culturing, qPCR, and sequencing.
Results
Approximately 46% of intact/viable bacteria and 40% of intact/viable fungi could be cultured with the culture media used during this study. This percentage is high when compared to spacecraft assembly cleanrooms on Earth where only 1 to 10% of intact/viable microorganisms can be cultured.
Furthermore, isolating organisms allowed scientists to conduct a separate study to examine the influence of microgravity and radiation on antibiotic resistance and virulence. This study discovered a novel species Enterobacter bugandensis that was associated with human disease on Earth.
"The implications of this study are not only limited to space biology but can have significant impact on cleanrooms here on Earth such as those in the pharmaceutical and medical industries."
Read the Publication
Characterization of the total and viable bacterial and fungal communities associated with the International Space Station surfaces, Aleksandra Checinska Sielaff, et al. Microbiome 2019
