Master of Science (MS)


Environmental Sciences

Document Type



This study evaluated the PCR inhibition and toxic effects by sediment samples exposed to drilling muds. This information was gathered in an attempt to identify what effect, if any, drilling muds had on the microbial community structure in sediments around four specific oil-drilling platforms in the Gulf of Mexico. Sediment samples were taken before and after drilling had taken place around two platforms (GB516 and VK916), and sediment samples were taken after drilling had taken place around two other platforms (MC292 and GB602). After using traditional, non-selective DNA extraction methods, successful amplification took place via PCR with all pre-drilling samples that were tested. Post-drilling samples, however, failed to amplify using the same procedure. Many experiments were conducted to identify the cause of PCR inhibition in the post-drilling samples. It was clearly demonstrated that an abundance of humic substances was being carried through the extraction procedure and caused the PCR inhibition. The Lumitox assay showed that the toxic effects of exposed sediments ranged from very toxic to non-toxic.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Paul LaRock