Lydia Pettit-- Dr. Raina Maier’s Laboratory

I am a senior majoring in Environmental Science with an emphasis on Microbiology. While taking Dr. Maier’s and Dr. Rich’s Environmental Microbiology class my sophomore year, I learned the importance of microbes, and how they are essentially the driving force behind all life on Earth. I declared my emphasis after that lecture, and went on to study Microbiology at the University of Leicester in the United Kingdom for a semester, for an experience I will never forget. Ultimately, I am interested in finding alternative solutions to some of the environmental issues of today, by understanding and utilizing the unique abilities that some microorganisms have to regulate processes important to the health of our planet.

 For my final semester here at the University of Arizona, I have joined Dr. Raina Maier’s laboratory, which focuses their research on the numbers, diversity and functionality of bacteria in low-nutrient environments. The amplification products from Polymerase Chain Reaction (PCR) are submitted for Illumina High throughput amplicon sequencing, which provides information on the genes present in the bacterial community. My project is to look at how the protocols used for extraction and amplification may be inhibited by certain elements found in the soil, sediments and mine tailings. Mine tailings are of specific interest, since they are heavily contaminated with metals, and lack soil structure and nutrients capable of supporting much biological activity and plant growth. Because of this, erosion of top sediments, and wind transport of contaminants are an issue for nearby communities. The high concentrations of heavy metals in the mine tailings have been known to be responsible for inhibition in processes such as PCR. So far from my research I have learned that the heavy metals, and possibly also the associated low pH are playing a role in reducing the quality and quantity of DNA that can be analyzed. By the end of the semester I hope to target some of these areas of inhibition, and develop an improved protocol for either extraction or PCR, that will increase the DNA yield and allow for more samples from low-biomass environments to be sent off for sequencing.