Biocides and Bacteria Kansas City, MO Flight Experiment, Mission 6 to ISS

Team Cosmic Supernova CO-PRINCIPAL INVESTIGATORS : Eamon Shaw Nicole Ficklin Holden O’Keefe St. Peter’s School Diocese of Kansas City – St. Joseph Teacher Facilitator: Robert J. Jacobsen, St. Peter’s School

Abstract The investigation aimed to determine the effects of the antibacterial agent liquid iodine on Escherichia coli bacteria in microgravity as compared to its effects in the gravity of Earth. The experiment was conducted aboard the International Space Station (ISS), with two controls on Earth. After testing, the researchers found that their hypothesis was proven: antibacterial agents in microgravity are shown to be less effective, as a result of microgravity inhibiting antibacterial power and/or the greater resilience of bacteria in a microgravity environment.

Statement of the Problem If an outbreak of dangerous bacteria was to occur on the International Space Station, it would need to be eliminated as quickly and completely as possible. Because of the substantial distance between Earth and the ISS, and the complicated and extensive process necessary to send anything to the International Space Station, a fast-acting and effective antibacterial agent would need to be available. For these reasons, the investigators tested the effects of liquid iodine upon Escherichia coli bacteria in microgravity. It was hypothesized that the E. coli would not be eliminated as well in microgravity as it would in the gravity of Earth. This is because microbes are known to reproduce faster in microgravity, and because of the fact that microbes in space are known to have evolved features, such as: a “column and canopy” structure not found on Earth and more biomass.

Experimental Procedure The experiment was conducted using a Type III Fluid Mixing Enclosure (FME) that was separated into three volumes. Volume 1 held a mixture of rehydration medium and liquid iodine for activation and elimination of the bacteria. Volume 2 held the freeze-dried E. coli bacteria, and Volume 3 held a glutaraldehyde solution (Grade II, 25% in distilled water) which acted as a fixative and inhibited bacterial growth at the conclusion of the experiment. Clamp A, separating Volumes A and B, was released five days before undocking, allowing the E. coli and liquid iodine to interact for three days time. Clamp B was released two days before undocking, allowing the E. coli and glutaraldehyde to interact, inhibiting bacterial growth and terminating the experiment. Two controls were conducted in conjunction with the investigation in microgravity: one containing iodine and one not containing iodine.

Interpretation of Data Once samples from all three FMEs were analyzed, it was determined that the control FME containing iodine had no living E. coli, the control FME that did not contain iodine had a great amount of bacterial growth, and the FME that was tested aboard the ISS contained far less living bacteria than the no-iodine FME. The living bacteria observed here were deformed and were much smaller than the bacteria observed from the no-iodine FME, but were still living nonetheless. This suggests that the iodine is less effective in microgravity. A possible reason for this could be that the antibacterial properties of iodine are not sufficient in microgravity, being that microbes are known to be more resilient in microgravity. Also, the substances aboard the ISS had less surface contact ; on Earth, gravity would pull the substances together, allowing constant contact (and elimination), while the opposite occurred in microgravity. As is the case with all scientific investigations, this was determined from the results of one test, and, of course, more tests are needed to be conducted to substantiate these findings.

CONTROL SAMPLE WITHOUT IODINE A microscopic look at the control sample after being conducted in gravity with no iodine. An abundance of E. coli can be seen, large and healthy. nbuoboui

Nmlnljb lk CONTROL SAMPLE WITH IODINE A microscopic look at the control sample after being performed in gravity with iodine. No E. coli can be seen.

EXPERIMENTAL SAMPLE k kh khkh A microscopic look at the sample after being conducted in the microgravity of the ISS. Traces of E. coli can be seen, though very small and highly distorted.

Acknowledgements Partner Institutions Benjamin Banneker Charter Academy of Technology aSTEAM Village St. Peter’s School Académie Lafayette Della Lamb Elementary Public Charter School Hogan Preparatory Academy Middle School Gemini Gentlemen Homeschool Group Notre Dame de Sion School Arrowhead Middle School Rosedale Middle School D.D. Eisenhower Middle School Argentine Middle School Boys and Girls Club of the Ozarks St. Teresa’s Academy Teacher Facilitator Robert J. Jacobsen Sponsors Distribution by Air Overland Park Microsoft Store University of Kansas School of Education GEAR UP Program St. Peter’s School PTA University of Central Missouri Cardelia Walker Real Estate Center for the Advancement of Science in Space National Center for Earth and Space Science Education