Acid mine drainage is globally among the most widespread and expensive forms of pollution.
This project will investigate how to use sunlight and natural microbial communities to provide
cost-effective remediation of pollution caused by mining (acid mine drainage), thus improving
access to clean water for humans and the ecosystems that support them. In addition, the
project will contribute more broadly to the development of methods and new understanding of
how microbial populations interact with minerals, organic compounds, and other microbial
populations in the environment. This understanding is crucial in order to harness the enormous
biotechnological potential of microbial systems that can be engineered to provide essential
services to human societies. The proposed work will improve environmental health, increase
diversity in the STEM pipeline, and strengthen international scientific collaborations. Women
and underrepresented graduate and undergraduate students will be recruited to work on this
project. This project will promote collaboration between U.S. and international researchers by
building on long-term relationships between the Spanish Geological Survey (IGME) and Penn
State, such that participants will benefit from international science and engineering training.
The goal of this project is to identify strategies to stimulate sulfide production in acidic pit lakes.
As a model system, we selected the anoxic deep layer of Cueva de la Mora (CM), a permanently
stratified acidic pit lake in SW Spain that is among the most intensively studied in the world.
Two competing hypotheses emerged from our previous research: 1) Sulfide production is
limited by organic carbon, or 2) Sulfide production is limited by zero-valent sulfur. The project
objectives are to: A) Stimulate autotrophic and heterotrophic sulfide production in laboratory
incubations inoculated with the CM anoxic layer microbial community; B) Resolve the metabolic
potentials and activities of the active populations in the stimulated communities; and C)
Identify interactions between microbial populations cycling C, S, Fe, N, and P under sulfide producing
conditions. Tasks to address these aims include: 1) Conduct a field campaign to
collect large quantities of biomass from the anoxic layer of CM; 2) Conduct laboratory
incubations to evaluate sulfide production under different conditions; 3) Sequence
metagenomes and metatranscriptomes to identify the most abundant and active microbial
populations; and 4) Construct conceptual species-level and community-level metabolic models
to generate new hypotheses about how to increase sulfide production and therefore
bioremediation potential. This project will contribute to a fundamental and mechanistic understanding of how
microorganisms interact to produce and consume sulfide in acidic environments, which is
crucial to mitigating the toxic effects of acid mine drainage. The results will advance knowledge
of previously undescribed and novel microbial species, including details of their metabolic
potentials, enzymatic machinery, and evolutionary relationships. There are currently only 1-2
sulfide-producing isolates able to grow at pH
higher and remains undescribed. Microbial communities in nature are made up of mutually
dependent populations that exchange metabolites, yet scientific studies rarely consider this
complexity explicitly. A significant merit of this proposal is that it focuses on a natural
environment with intermediate complexity, appropriate for expanding and adapting modeling
tools developed for laboratory cultures for natural ecosystems. Documenting microbial
interactions in communities is key to understanding community assembly and to harnessing the
enormous biotechnological potential of engineered microbial systems that can provide
essential services to human societies.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
|Effective start/end date||6/1/21 → 5/31/23|
- National Science Foundation: $215,941.00