New Mexico Geological Society Annual Spring Meeting — Abstracts

Valles Caldera is an active caldera in Northern New Mexico that formed 1.25 million years ago. Most of the caldera is within a National Preserve that, according to the National Park Service, is visited by 30,000-76,000 visitors each year. The western margin of the Preserve contains an area where CO₂ and H₂S-rich volcanic gases are emitted through fumaroles that sometimes interact with surface waters, creating acidic and sulfidic springs, streams, and lakes that support diverse acidophilic microbial communities. The greater Valles Caldera ecosystem also includes natural and artificial hot springs along the Jemez River to the south. Soda Dam is one of these travertine springs, in which sulfidic, volcanically-heated waters host robust microbial biofilms where dissolved volcanic gases are exposed to light and oxygen. We characterized metagenome-assembled genomes from six samples collected in acidic streams, lakes, and mudpots in the Sulfur Springs and Alamo Canyon region of the Preserve, and two samples from circumneutral springs at Soda Dam. We will share metagenomic insights into the extremophilic microbial communities in the region, including metagenome-assembled genomes from known extremophilic sulfur-oxidizing bacterial and archaeal genera including Acidithiobacillus, Halothiobacillus, Acidianus, Ferroplasma, and Sulfurovum, as well as currently undescribed microorganisms such as family “RAAP-2” in the Actinobacteriota, family “UBA5754” in the Desulfobacterota, and unnamed groups in the order Thermoplasmatales. We will discuss how these novel microorganisms fit into the ecological niches present in the volcanically-influenced landscape, and how they might impact sulfur and carbon biogeochemistry in the region.

The metagenomic analysis for this project is being conducted as part of a research-based class at New Mexico Tech, Metagenomic Analysis (GEOB 589-01/BIOL 589-01, Spring 2023). All students in the course contributed to the analysis of these datasets, and are included as co-authors.