Together with our collaborator Susan Lang at the University of South Carolina, we have published a new paper on the use of deep carbon by microbes at the Lost City Hydrothermal Field. This study addressed the question: how much of the carbon formed deep in the Earth's interior is fueling microbial activity in the Lost City chimneys, and which microbes are using that carbon? The surprising answer is that methanogenic archaea are unable to use the deeply-sourced carbon and depend on other organisms, such as sulfate-reducing bacteria, to metabolize the deep carbon and convert it into other carbon compounds. We will continue pursue this story with our upcoming expedition to the Lost City in September 2018.
Postdoctoral Researcher, Katrina Twing, participated in a Chief-Scientist Training Cruise focusing on the use of Deep Submergence Vehicles in July onboard the R/V Atlantis. In addition to learning about leading oceanographic research expeditions and the latest uses of ship-to-shore communications (also known as telepresence), Katrina got the opportunity to dive in the HOV Alvin. During her dive, she tested out a large-volume in situ sampling device our group is helping develop for use on our future expedition to sample the Lost City Hydrothermal Field. More details about the sampling device and her experience with Alvin can be found at https://vimeo.com/191864900.
The Brazelton Lab has teamed up with U of U geologist Brenda Bowen and Westminster College microbiologist Betsy Kleba in an interdisciplinary study of salt crust formation on the Bonneville Salt Flats. In September 2016, Julia and Emily collected samples from the upper crust of the Salt Flats. These samples are being used for enriched carbon incubation experiments as well as for one of the first metagenomic studies of this unique environment.
Several members of the lab and collaborators are co-authors on a new open-access paper in PeerJ that reports metagenomic data from serpentinite springs at the Voltri Massif in northern Italy. The springs are ultra-basic (pH 12) and have extremely low biomass. One of the springs is nearly sterile, so we spent 4 days on site filtering >500 L of water, from which we were able to recover only 50 nanograms of pure DNA for sequencing. The low biomass is probably a result of the extreme conditions created by susburface serpentinization reactions, which are expected to have been prevalent on the early Earth, Mars, and other planetary bodies. Read more here.
The results in this new paper include identifications of specific archaeal and bacterial species that are enriched in the pH 12 springs, evidence that some of them are capable of methane production or methane consumption, and some initial functional predictions from the metagenomic assemblies. Future studies by the lab will integrate these results with data from additional serpentinite springs around the world in order to gain a broader understanding of the relationships between serpentinization and life.