Norah Aljahdali, Jonna Coombs
Abstract: Cryptic plasmids from bacteria which had been isolated from the deep terrestrial subsurface of the Savannah River Site (SRS), Aiken, South Carolina were characterized. This study examined two strains of bacteria, Comamonas sp. B0669 and Pseudomonas spp. B0623. The aim of the study was to characterize two cryptic plasmids and verify previous microarray analysis by using DNA sequencing to find genes that encode heavy metals resistance. During the project the focus of the study changed from Comamonas sp. B0669 to Pseudomonas spp. B0623 because the yields of purified DNA were too low and the technical difficulties occurred with the very large plasmid from Comamonas sp. B0669. The plasmid of Pseudomonas spp. B0623 was purified and characterized using restriction digest enzyme analysis, followed by DNA ligation with a vector (pUC19) and transformation into competent cells (E.coli Xl1-Blue). This study has potential applications in bioremediation to treat sites contaminated with heavy metals, and can provide information on the biology of microorganisms living in the deep subsurface.
Keywords: Plasmid, Subsurface bacteria, Pseudomonas spp B0623, Heavy metals