Microbial membrane features and metabolic pathways in deep fractured shale systems
EMSL Project ID
50428
Abstract
Humans are currently engineering the deep subsurface at unprecedented scales for the purposes of energy-capture technologies, energy-storage capabilities, and environmental mitigation strategies. To address the need to develop a mechanistic and predictive understanding of fundamental ecological, biogeochemical, and microbial processes occurring in the subsurface (EMSL Environmental Sciences Area), this work investigates growth kinetics, membrane features, and metabolite production of model bacteria isolated from hydraulically fractured shale environments. Specifically, ongoing experiments are aimed at cultivating Halanaerobium, Marinobacter, and a produced water consortium across a range of temperatures, salinities, and redox conditions to elucidate 1) how broad environmental gradients drive metabolic processes and rates through proteomic and metabolomic characterization and 2) how cells balance membrane permeation and rigor through characterization of the lipidome. Previous metagenomic characterization of microorganisms in the fractured shale systems has improved our understanding of metabolic potential for dominant shale taxa, but we have much to learn as to how environmental and biogeochemical conditions drive cellular features and metabolisms. Microbial membranes protect the cell from its surrounding environment by regulating membrane permeability and fluidity under changing salinities, temperatures, and nutrient availability. Membrane charge and structure also plays a critical role in interactions between cells, extracellular polymeric substances, and rock matrix surfaces. Our preliminary analysis of membrane lipids extracted from produced fluid collected from a hydraulically fractured shale well the Marcellus formation shows an increase in anionic glycosidic head groups with elevated salinity, suggesting membrane chemistry is strongly influenced by the need to balance osmoprotection with bio-energetics. Here, we extend this analysis to directly test the effect of environmental conditions on cell features through controlled laboratory experiments using model bacteria. We request analysis of small metabolites (NMR), proteins (HR-MS), and lipids (HR-MS) for samples collected from continuous culture experiments to better characterize these environmental effects on microbial metabolisms and lipid chemistry. Requested analysis will improve our understanding of how genomes predict metabolic/membrane pathways across broad environmental gradients and lead to an improved predictive understanding of biogeochemical drivers in energy capture systems.
Project Details
Project type
Exploratory Research
Start Date
2018-10-21
End Date
2020-02-29
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Colosimo F., A.R. Wong, E.K. Eder, H.M. Brewer, S.O. Purvine, D.W. Hoyt, and M.S. Lipton, et al. 06/16/2020. "Metabolic and membrane adaptations of the hydraulically fractured shale isolate Halanaerobium in response to temperature and growth rate fluctuations under continuous culture." Abstract submitted to International Water Conference, Utrecht (The Netherlands), Netherlands. PNNL-SA-148928.