Collaborative Research: Experimental determination of petroleum biodegradation patterns from a genomically-informed analytical vista

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

Intellectual merit: This proposal describes a series of laboratory studies designed to assess the genomic and molecular patterns of petroleum biodegradation under a range of conditions relevant to the Earth?s surface and subsurface. The concerted application of comprehensive, two-dimensional gas chromatography, Fourier transform ion cyclotron resonance mass spectrometry, and pyrosequencing-based metagenomics will provide unparalleled insight into petroleum biodegradation and the responsible microbes, and distinguishes this work from any previous studies. The primary hypotheses to be tested are the following: 1) Hydrocarbon biodegradation by microbes acts simultaneously on thousands of distinct compounds, not in a strictly stepwise fashion. 2) Hydrocarbon preference pattern and associated genomic potential for a microbial community are controlled primarily by the redox potential of the terminal electron-accepting process. 3) High-molecular-weight and polar compounds are bio-transformed through incomplete oxidation and structural alteration, not through complete remineralization. These hypotheses will be tested by conducting time-series laboratory experiments in which petroleum is biodegraded with different electron acceptors and at different temperatures. The loss and gain patterns for molecules within each treatment and differences across treatments in these patterns and in genomic content will provide the data to test these hypotheses. Results are further anticipated to reveal novel metabolic actions and genomic capacity, and yield molecular degradation patterns that can relate environmental genomic and petroleum content to the relevant biological processes. New data analysis tools will also be developed and validated. Broader Impact: Results from this research will contribute broadly to an understanding of petroleum biodegradation and carbon cycling in the Earth system, and will be broadly disseminated through popular outlets with assistance from a professional artist. Knowledge gained from this research will also be translated directly to federal agencies including the NOAA?s Assessment and Restoration Division, as well as to private industry through existing corporate ties. Direct educational impacts of this research include the training and education of high school, undergraduate, and graduate students, as well as the advanced training of postdoctoral researchers. High school students will be incorporated through existing summer research programs targeting students from underserved regions. Undergraduate students will be incorporated into all aspects of the proposed research through integration into coursework and REU support. Mentoring of a graduate student and postdoctoral researchers will be provided by the PIs.