Microbial Astronauts

Do you want to increase your productivity? Buy a ticket for the next spaceflight!

It may work... if you are a microbe with the ability to produce an interesting metabolite, such as an antifungal agent. The treatment involves some kind of unknown mutation, but that's OK as long as you become a better producer with a stable behavior.

Scientists from Zhejiang University and Shandong Lukang Pharmaceutical Co. (China), recently published the following article (open access):

Jingle, L., Jianping, L., Zhinan, X., Wei, S., Peilin, C. (2007). Space-flight mutation of Streptomyces gilvosporeus for enhancing natamycin production. Chinese Journal of Chemical Engineering, 15(5), 720-724. Link to publication.

Streptomyces gilvosporeus is a bacterium that produces natamycin (also known as pimaricin), which is an antifungal agent used as a treatment for fungal keratitis and also as a food preservative. Tubes containing spores of this microbe were placed in a sample module of a returnable satellite, which was launched from the Jiuquan Satellite Launching Center in Gansu Province, China. After orbiting the earth for 18 days, the bacterial taikonauts landed safely in a returning module. Then, ground-based scientists grew these spores and studied their colony morphology, survival rate, and natamycin production. As compared to similar spores that had never left the Earth, some of the space travelers behaved differently. This was expected, and most likely due to mutations produced by the spaceflight conditions (including cosmic radiation, microgravity, and vacuum). After selecting for the best natamycin producers, a stable overproducer strain was isolated.

The authors cite other reports on the use of spaceflight for obtaining improved microbial strains. But, more generally, the relationship between microbes and space is fascinating, involving different aspects such as:

• physiological responses of microbes to spaceflight conditions (affecting growth, pathogenicity, production of interesting metabolites...),
  
• health of astronauts (microgravity weakens the immune system, which might make astronauts prone to infections),
• microbial contamination of spaceships (terrestrial microbes landing on other worlds, and vice versa?),
  
• panspermia theory and the origin of life,
• etc.

Some links:

- NASAexplores: Microbes in Space!
- Microbes May Threaten Lengthy Spaceflights, washintonpost.com.
- NASA Study Will Help Stop Tiny Stowaways To Mars, ScienceDaily.
- Russian rocket carries experiment to be analyzed at MSU, Montana State University.
- Spaceflight shown to alter ability of bacteria to cause disease, Biology news Net.
- Microbial responses to microgravity and other low-shear environments, Microbiol Mol Biol Rev.