Guest Post – Stadium Seat Bacteria

Guest blog post from David Coil, first author of the recently published article “Porphyrobacter mercurialis sp. nov., isolated from a stadium seat and emended description of the genus Porphyrobacter“.

Cell phone sampling

This paper is our first attempt at entering the world of bacterial taxonomy and the description of a new species. The background for the project is an effort called Project MERCCURI which was a nationwide citizen science effort to collect samples to grow on the International Space Station (ISS), to collect samples from the ISS, and to do a nationwide biogeography study of cell phones and shoes. More information on the project can be found here.

We wanted to both do some interesting science, and engage the public in getting excited about microbiology and about space research. We held sampling events around the country, mostly organized by Science Cheerleader which is an organization of present and former professional cheerleaders with degrees in math and science.

To this end we screened hundreds of bacterial colonies, looking for a diversity of organisms as well as to ensure that we only sent BSL-1 bacteria to the ISS. As one might expect we saw tons of Bacillus, Micrococcus, etc. Every full-length 16S sequence was shipped off to BLAST and we slowly worked our way through the list.

One day however, I put in a sequence that showed only 95% identity over the entire 16S gene to anything with a name. Excited at the prospect of having a new species, we immediately set out to redo the sequencing… and got the same result.

Shoe sampling

This particular bacteria had been collected by a professional cheerleader, Taylor Hooks. She led a sampling event with the local youth cheerleading squad, the Coronado Islanders. Girls from the youth squad sampled their cell phones and shoes as part of the biogeography study that we’re still analyzing data for. At the same time, Taylor sampled some surfaces in the area, including a stadium seat where they were practicing. When identifying isolates from that sample, we found this one isolate that was sufficiently novel to be a new species.

The Dragon spacecraft and Falcon 9 rocket carrying the project

The Dragon spacecraft and Falcon 9 rocket carrying the project

I thought that describing a new bacterial species would be a great undergraduate project so I offered it to Andrew Stump who had just joined our lab. We began the process of trying to understand what was required for a formal description of a species so began the long slog. So we finally got it all together, described a new genus and species called “Kirrobacter mercurialis” and sent the paper off to PeerJ.

It was their first new bacterial species description so there was a bit of learning on both ends. If anyone out there thinks that open-access equates to easier or softer peer review… they should read the reviews that we got back on this paper. t was sent out to 3 reviewers all of whom trashed the paper in exquisite detail. I have never had a submitted paper so thoroughly dismantled in virtually every aspect. And they were right. The (sadly anonymous) reviews were all written by people who clearly had a lot more expertise in the field than we did. Thus began the second round… I spent an entire month just on phylogenetic trees.

At the end of which process we changed from the proposed new genus and species, to a new species within the existing genus of Porphyrobacter, for which we had to amend the formal description of the genus. The second round of review was also constructive, but much faster than the first round.

I love this paper for many reasons, including the fact that this is probably the first ever description of a new species to contain the phrase “No statistically significant difference in growth was observed between earth and microgravity aboard the International Space Station (ISS).