Lisa Alverez-Cohen, Ph.D.
University of California Berkeley
NIEHS-funded researchers demonstrated that natural microbial communities amended with acetylene can break down chlorinated contaminants, and in the process, they discovered a new bacteria species. Acetylene, produced in aquifers when certain minerals interact with trichloroethene (TCE), usually interferes with the ability of microbes to dechlorinate TCE. TCE is a chlorinated compound that can contaminate the environment and has been linked to health outcomes like cancer.
Previous lab studies by the team showed that acetylene could act as an energy source for certain bacteria, which could then continue to degrade TCE. To explore this finding in natural systems, they combined laboratory studies of natural microbial communities with computational approaches and metagenomic analyses to characterize the community. The scientists examined microbe metabolism and community functions to determine which bacteria could use acetylene for energy while breaking down TCE.
First, they took samples from a site contaminated with TCE and used acetylene to enrich the microbes that could it as an energy source. They continued adding TCE to examine at dichlorination and observed unique metabolic interactions previously only reported in synthetic, laboratory settings. The researchers also identified novel acetylene-eating bacteria in the phylum Actinobacteria.
According to the authors, native bacteria that can use acetylene as an energy source may be more common than previously thought — useful for developing effective bioremediation strategies to clean up contaminated sites.
Citation: Gushgari-Doyle S, Oremland RS, Keren R, Baesman SM, Akob DM, Banfield JF, Alvarez-Cohen L. 2021. Acetylene-fueled trichloroethene reductive dechlorination in a groundwater enrichment culture. mBio 12(1):e02724-20.