Team:Penn/CdTolerance

We are especially interested in using AMB-1 for bioremediation applications, such as cleaning pollutants from water. Many engineered microbes can absorb pollutants, but if AMB-1 were used instead of E.coli, it could be subsequently removed from the water with a magnet – effectively removing both the pollutant and the engineered microbe.

In order to appropriately determine the effectiveness of using AMB-1 as a viable bioremediation alternative to E.coli, we performed tests to measure the natural tolerance of both strains to the pollutant cadmium. The experiment allowed us to identify the threshold concentration of normal growth of bacteria. We used the tests to ensure that the AMB-1 strain could withstand the levels of cadmium present in polluted environments.

From the data, we can conclude that Magnetospirillum magneticum AMB-1 maintains normal growth under 10 uM concentration of cadmium and showed no growth in media with above 100 uM of cadmium ions. E.coli showed unaffected growth in media with less than 500uM of cadmium ions and showed zero growth with 5000uM of cadmium ions. Although E.coli seemed to be inherently more tolerant towards cadmium than AMB-1, the data does show that AMB-1 can tolerate cadmium concentrations usually toxic to ecosystems. This shows that the strain could potentially still be a viable bioremediation tool.