Proliferation of Spacecraft-Associated Acinetobacter on Ethanol
Authors:Hania Brasali, Ivonne Cepeda, Trevor Gornick, Chirag Jain, Rakesh Mogul, Alex Oei, Joseph Rodriguez, Alexa Wollen
Mentor:Rakesh Mogul, Associate Professor of Biological Chemistry, Cal Poly Pomona
Efforts to minimize the biological contamination of Mars, as a result of spacecraft exploration, are critical to ensuring the integrity of future life detecting missions. Among the differing microorganisms detected in the assembly facilities for Mars spacecraft (in relative high abundance) are the <i>Acinetobacter</i>, which are Gram-negative and non-spore forming bacteria. Accordingly, our current efforts are focused on measuring the potential for spacecraft-associated <i>Acinetobacter</i> to proliferate on the cleaning solvents of ethanol and isopropanol, which are used in the spacecraft assembly process. Our work demonstrates that <i>A. radioresistens 50v1</i>, which was isolated from the surface of the preflight Mars Odyssey orbiter, is able to proliferate on ethanol under minimal salt conditions, and that the growth is enhanced in the presence of iron, but inhibited in the presence of zinc. The growth rate of the 50v1 strain under minimal conditions is ~ 0.17 h-1, which is roughly 2-fold greater than that of the control <i>A. radioresistens</i> type strain. The contributions of alcohol dehydrogenase to the growth on ethanol will be discussed. In summary, our results suggest that <i>A. radioresistens 50v1</i> may utilize spacecraft cleaning solvents as energy sources, and hence may have adapted to the selective pressures of the spacecraft assembly facilities.