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Nature's Helpers: Hydrogen-Based Microbial Interactions for Successful Bioremediation

Speaker: Rosa Krajmalnik-Brown, Arizona State University
Series: Special Seminars
Location: Friend Center 004
Date/Time: Thursday, May 9, 2019, 12:30:00 p.m. - 01:30:00 p.m.


Rosa Krajmalnik-Brown

School of Sustainable Engineering and the Built Environment
Biodesign Swette Center for Environmental Biotechnology

Bioremediation using microorganisms is a promising approach to remove organic and inorganic contaminants from soil and groundwater. For example, under anaerobic conditions, Dehalococcoides can reduce toxic chlorinated ethenes to ethene, an innocuous product, and gain energy for growth in the process. My laboratory devises microbial platforms to study microbial interactions in order to optimize remediation reactions. We look at competing processes present as part of the natural soil biogeochemistry in pristine and contaminated  environments and study these processes through a combination of enrichment techniques, molecular microbial ecology (deep sequencing), water chemistry, and electron balances. Important microbial interactions for anaerobic remediation include those centered around hydrogen, such as interactions with methanogens and acetogens. We currently explore the importance of harnessing these interactions in contaminated and pristine sediments for successful bioremediation prediction. We have applied the knowledge gathered to: 1) enrich  microbial dechlorinating cultures capable of some of the fastest rates of dechlorination for TCE to ethene reported, 2) successfully design and operate different types of continuous dechlorinating reactors, and 3) demonstrate that our approach can work at the field scale. Our successful outcomes are due to our  multidisciplinary approach that links microbiology and engineering. The results gathered to date also provide fundamental understanding of microbial identification and enrichment techniques that we now apply to enrich microbes that can reduce chemicals such as Carbon Monoxide and Heavy metals.

Jointly held with the Department of Chemical and Biological Engineering