Jaron Bergin, Probing For Atmospheric Bacteria Capable Of Polycyclic Aromatic Hydrocarbon Degradation Faculty Chair: Dr. Henry Spratt
The presence of DNA encoding a Glutathione S-Transferase (GST) was verified in atmospheric samples utilizing standard molecular techniques and previously described nucleotide primers. GSTs are enzymes that bind, transform, and detoxify electrophillic compounds such as polycyclic aromatic hydrocarbons (PAHs). Atmospheric samples were collected by drawing 1630 m3 of air through PM10 monitoring equipment and onto 8" x 10" quartz microfibre filters over a 24 hour sampling periods. Resulting DNA was extracted and amplified via the Polymerase Chain Reaction (PCR). PCR reaction products were subsequently separated through gel electrophoresis. Bacterial DNA was separated on 1% agarose stained with ethidium bromide. GST electrophoresis reactions were conducted using 3% MetaPhor agarose stained with SYBR Gold. 16S PCR results
were digested with restriction enzymes Not! and EcoRl and separated by gel electrophoresis. Samples resulting in different banding patterns were sequenced in order to identify potential organisms present as sample sites. Additionally, Phospholipid Fatty Acid (PLFA) analysis was conducted on atmospheric samples indicating general community structure and quantifiable differences between sample sites. The presence of Bacterial DNA and GST-encoding DNA was verified in all samples. Also, sequence analysis identified the potential presence of PAH degrading bacteria at both sample sites. Further work in this area may determine levels of GST expression and verification of this pathway as a method of PAH degradation at sites within the Chattanooga, TN area.