Javier Peralta '21

Summer Research Scholar with Margaret Anne Hinkle

This summer, I had the opportunity to work under the supervisor of Professor Hinkle in W&L's geochemistry lab. My research focused on fungal bioremediation of manganese oxidizes from coal mine drainage (CMD) and how various buffers can impact the biogeochemical process.

As with any mining operation, coal mining creates a significant amount of wastewater, which is then treated for heavy metal contamination. Manganese is usually the final heavy metal that is remediated from the wastewater. It is typically dissolved into the water as a Mn (II), making it soluble and difficult to remove. To facilitate its removal, the manganese is typically oxidized to Mn (IV) through abiotic processes, allowing it to bond with oxygen and create minerals such as δ-MnO2. This mineral can then be used for scavenging other toxic heavy metals present in the water given its layered/tunnel atomic structure.

Although abiotic processes are usually employed to oxidize the manganese, bioremediation has drawn a lot of attention given the speed at which it occurs. Studies that have looked at the rate of biogenic formation of δ-MnO2 claim that microorganisms can accelerate oxidation by five orders of magnitude over abiotic oxidation. Moreover, a shift to bioremediation of manganese can prove to be more cost effective and is less likely to form by-products. Despite the potential benefits, there is still a great lack of knowledge when it comes to understanding how microorganisms, such as bacteria and fungi, are capable of oxidizing manganese is such an effective way.

In an effort to add to the body of knowledge of geomycology, my research looked into how employing distinct buffers impacted the fungi's oxidative capacities, with the hope of finding a buffer that has the least effect on the process. We did this by culturing six different sample sets of Paraconiothyrium Sporulosum in AY media with designated buffer in each set, as well as a Mn-free sample set and a buffer-free control. Once the sample sets were made, the fungi were stored and allowed to grow for about two weeks. The pH was checked and recorded every day, a small amount of media was collected each day for UV-VIS analysis, and pictures were taken to track changes in fungal growth. After two weeks, the fungi were prepared for SEM-EDS analysis, the remaining filtrate was collected, and the pH and Mn (II) data was compiled for spreadsheet analysis.

Spending my summer in Professor Hinkle's lab was an incredible experience for me. Her lab environment allowed for me to both learn from her guidance and experience but also required me to be independent and free thinking when it came to my work and my research. I learned valuable skills in general research protocol as well as gained a variety lab skills and techniques. I was exposed to the literature behind my project, gaining an insight on how scholars seek to understand the natural world and its overwhelming intricacies. Overall, I came to realize how little we know as fact, which sparked within me a desire to further pursue research opportunities in geology.

Summer Research Scholars