Metagenomic comparison of subsurface basement sites



The oceanic crust represents one of Earth’s last biological frontiers as it is difficult to access. Here, I will analyze metagenomes from two distinct low biomass (<104 cells/cm3) basement sites from IODP Expedition 360 (Atlantis Bank) and Expedition 370 (Nankai Trough). Atlantis Bank represents gabbroic lower oceanic crust, and Nankai Trough represents basaltic upper oceanic crust with significantly higher temperatures. Metagenomics can inform us of the microbial functional potential and community composition present. I will compare genes present in these two systems and this information can address hypotheses about microbial survival mechanisms employed in high temperature settings, and if hydrogen acts a major source of energy in these environments.



Eight thousand miles away from Texas lies my hometown in Malaysia, a city called Kuantan, and it was in high school was where my fascination with biology first began. Attracted by the research opportunities present, I traveled to Montana State University in pursuance of a degree in biological engineering. Here, I was first introduced to the microbiology of extreme environments, where I worked on samples from Antarctica with Drs. Heidi Smith, Christine Foreman, and Connie Chang. During my undergraduate studies, I also enrolled in classes where I learned about deep-sea microbiology. I was intrigued by how these microbes survive and adapt to extreme environments. This curiosity led me to apply for a graduate program in the Department of Oceanography at Texas A&M University, where I now work with Dr. Jason Sylvan. My master’s thesis focused on the microbial communities present in enrichment incubation experiments using basement samples obtained from Atlantis Bank, Southwest Indian Ridge on IODP Expedition 360. The primary motivation for my Ph.D. dissertation is to characterize the microbiology of basement and seafloor basalt samples from mid-ocean ridges. I am working with samples from the East Pacific Rise 9°N, and participated in IODP Expedition 393 to the Southern Mid-Atlantic Ridge to retrieve basement samples for microbiological analysis. With the Schlanger Fellowship, I will compare the metagenomes of in situ basement samples obtained from two distinct sites: Atlantis Bank (Expedition 360), and Nankai Trough (Expedition 370). This data set will provide insight on the survival mechanisms utilized by the microorganisms, and if the strategies employed by the microbial community present is influenced by the different lithologies and in situ temperatures.