Filipowicz, Urszula I.. The effects of copper on the soil bacterial community in an agricultural soil. Retrieved from https://doi.org/doi:10.7282/T36W99V8
DescriptionCopper is an essential trace element needed for microbial growth and development; however, it is also toxic in higher concentrations. Typical background levels of copper in U.S. soils range from 5 to 50 µg/g dry weight. Elevated copper levels are hypothesized to cause a shift in the soil microbial community resulting in more copper resistant microbes. With the objective of evaluating major shifts in soil bacterial community composition as a result of elevated copper concentrations, three sets of soil microcosms were constructed using an agricultural soil collected from the Adelphia Freehold Research Center. The shifts in the bacterial community within the microcosms were investigated through denaturing gradient gel electrophoresis (DGGE). These data revealed the emergence of a variety of bacteria in the presence of elevated copper. Results indicated that a bacterium most similar to the order Sphingobacteriales was present in 500 µg/g copper amended microcosms, with no additional carbon supplementation after 91 days of incubation. A Chloroflexi-like bacterium was shown to be tolerant of copper in the 250 and 500 µg/g copper amendments after 14 days of incubation. A bacterium from the phylum Actinobacteria was present in highly copper contaminated microcosms (2,000 µg/g). In addition, a microorganism most closely related to the Arthrobacter sp. was shown to be tolerant of 500 µg/g copper, however only while in the presence of an added simple carbon source. Lastly, a bacterium belonging to the Rubrobacteraceae family of Actinobacteria was revealed in copper amended soils regardless of whether a carbon source was supplemented. The presence of these copper tolerant bacteria in a previously uncontaminated agricultural soil suggested a native copper resilience within the bacterial community.