Biocides and BacteriaKansas City, MO

Flight Experiment, Mission 6 to ISS

Team Cosmic SupernovaCO-PRINCIPAL INVESTIGATORS:

Eamon ShawNicole FicklinHolden O’Keefe

St. Peter’s SchoolDiocese of Kansas City – St. Joseph

Teacher Facilitator:

Robert J. Jacobsen, St. Peter’s School

AbstractThe 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 ProblemIf 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 ProcedureThe 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 DataOnce 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.

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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

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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.

AcknowledgementsPartner InstitutionsBenjamin 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 FacilitatorRobert J. Jacobsen

SponsorsDistribution 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