Use of Different Surfaces and Sizes of Nanoparticles to Capture Bacillus megaterium on Spacecraft

Undergraduate #95
Discipline: Nanoscience
Subcategory: Microbiology/Immunology/Virology

Altoneisha Rose - Southern University at New Orleans
Co-Author(s): Christian Clement, Pamela Marshall, and Illya Tietzel, Southern University at New Orleans, New Orleans, LA

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Bacteria of the genus Bacillus in the spacecraft such as the space shuttle and the International Space Station create a problem for the astronauts in space because it has been shown that bacteria are more virulent in this environment. Also biofilms of bacteria can compromise equipment. Since there are limited ways to get supplies in space there should be an easy way to be able to detect and eliminate the bacteria in spacecraft. Nanoparticles don’t take up much space and have been shown as a possible way to interact and possibly capture bacteria. Sulfate, carboxylate and amino nanoparticles of different chemistries were used in the past and interacted with bacteria. Also, carboxyl and sulfate polystyrene nanoparticles can bind microbial biofilms. Therefore, it is hypothesized that nanoparticles of different surface chemistries and sizes will differ in their ability to capture bacteria.

To test the hypothesis, the capture procedure started with serial dilutions of nanoparticles of various surface chemistry and sizes (amino, sulfate, and carboxylate; 50 – 1000 nm) with Bacillus megaterium to initiate the interaction of bacteria to nanoparticles. The mixtures were then brought into close contact by rotating gently on a Boekel rotator for a constant speed and time which enabled the capture of bacteria. Next, the samples went through a washing process using a centrifuge that isolated the nanoparticles that were bound with bacteria from ones unbound with these microbes. In order to count the amount of captured bacteria with the different types of nanoparticles the product of the centrifugation was used for a standard plate count.

There were three controls for the experiments. One control was nanoparticles alone, the second control was bacteria alone. Both went through the same treatment as the samples. The third control was untreated bacteria. The presence of Bacillus megaterium was also assessed through the use of polymerase chain reaction. The results showed carboxylate nanoparticles captured 2,250,000 compared to 30,350 bacteria/ ml without use of nanoparticles. PCR detected the bacterium. Same concentrations of nanoparticles with different sizes showed different numbers of microbes. In conclusion, capture of bacteria using nanoparticles is effective. Also, there is a difference in capture between the different surfaces and sizes. Further tests will be done to test the ability of the same nanoparticles to bind different bacteria of different types.

Funder Acknowledgement(s): Funding by NSF DBI URM to I. Tietzel./ Funding by NASA EPSCoR (RAP) to I. Tietzel.

Faculty Advisor: Illya Tietzel,