The Microbial Jungle, the Final Frontier

A new microbe called Tersicoccus phoenicis is a member of the bacterial family Micrococcaceae. It has only been found in spacecraft clean room facilities. Photo credit: NASA/JPL-Caltech

A new microbe called Tersicoccus phoenicis is a member of the bacterial family Micrococcaceae. It has only been found in spacecraft clean room facilities. Photo credit: NASA/JPL-Caltech

I've mentioned before that harmless microbes can pose more of a problem for astronauts when they travel up into space. This threat is exactly what prompts NASA to be very careful working in clean rooms constantly subjected to harsh sterilization protocols to eliminate any microbes. Microbiologists also conduct regular surveys with swab kits to determine which microbes may be still sneaking aboard our equipment and traveling into space.

These kinds of microbial surveys are what led to the discovery of a new microbe named Tersicoccus phoenicis in two spacecraft clean rooms in Florida and South America.

This new microbe's name is Tersicoccus phoenicis. Tersicoccus loosely translates from Latin to the clean, rod-shaped bacteria. phoenicis refers to NASA's Phoenix Mars Lander that was in the works when this bacterium was isolated back in 2007. 

Photo Credit: NASA Goddard Photo and Video http://www.flickr.com/photos/24662369@N07/7217592194 cc: http://creativecommons.org/licenses/by/2.0/

Photo Credit: NASA Goddard Photo and Video http://www.flickr.com/photos/24662369@N07/7217592194 cc: http://creativecommons.org/licenses/by/2.0/

One down, how many more to go?

Estimates of the number of different microbial species is usually staggering. For example, Curtis et al 2001 suggest the upper limit for bacterial species is two million. And that’s just in the ocean. They also estimate there are four million different species in one ton (2,000 pounds) of soil.

If you are interested in diving into the primary literature on this topic, Jonathan Eisen put together a great collection of papers on Mendeley worth checking out.

Where are all these microbes hiding?

Microbes can be found in nearly all environments. For example, they can be found all over the outside and inside of our bodies. These bacteria help us in numerous ways including protecting us from disease and aiding in digestion. We have also found microbes in the most extreme environments on our planet including boiling hot geysers, within ice in the arctic, and even floating in the atmosphere.

So, where haven’t we looked yet?

The truth is that finding microbes in extreme environments can be relatively easy.

Just because we find microbes in extreme environments doesn’t mean that these extreme abilities are easily acquired. For example, the extraordinary ice-forming ability of Pseudomonas, which I covered before, likely evolved over millions of years. As such, extreme environments typically have a smaller number of microbes present and therefore make them easier to find and study.

The species we haven’t yet discovered? These species are likely hiding in plain sight.

Dan Dykhuizen explains in another estimate that there are about 20,000 common microbial species with an additional 500,000 rare microbial species in small amount of soil. The challenge is that these common species are so much more abundant than these rare species that we have difficulty finding them.

Although we’ve never seen this microbe before, T. phoenicis could normally live outside in the soil in low numbers. In the clean room, the other species that normally outnumber T. phoenicis are eliminated by the harsh clean room environment, which led us to discover T. phoenicis.

Photo Credit: t_buchtele at http://www.flickr.com/photos/54908576@N00/3422507814/ cc: http://creativecommons.org/licenses/by-nc-nd/2.0/

Photo Credit: t_buchtele at http://www.flickr.com/photos/54908576@N00/3422507814/ cc: http://creativecommons.org/licenses/by-nc-nd/2.0/

Are these rare species even important?

Why should we care about these rare species? These species might be rare because they’re just not as good at living in these environments as the common species, or represent species that are going extinct.

On the other hand, perhaps we should study and preserve these rare microbes simply because they are there, as Fletcher Halliday suggested.

Rare microbes may also be much more important than we think.

For example, a microbe called Chromatium okenii, only representing 0.3% of the total microbial population in Lake Cadagno, was found to contribute more than 40% of the ammonium uptake and 70% of the carbon uptake by the entire population.

T. phoenicis is also really good at withstanding the harsh cleaning regimes of NASA. Understanding the basis for these abilities could teach us something amazing we haven’t seen before, and lead to advancements in science and technology. For example, understanding why T. phoenicis can survive in these clean rooms may lead to better cleaning products.

Similar to how these spacecraft clean rooms selected for this rare microbe, the people at microBE.net are asking important questions about how modern construction and our obsession with sterility alters the microbial ecology of the built environment, and whether or not this change in exposure and selection for rare microbes is a good thing or not.

Want to explore strange new worlds? You may not need to go very far. The microbial jungle is at your fingertips and right outside your door. Don’t forget to check out more of our posts below and remember, stay hungry!