The synergistic toxicity of excess Copper and Nickel in Escherichia coli

Authors: Carlos RodriguezBornot, Jennifer Goff, Linda Darwiche, Rebecca Ingrassia

SUNY Campus: SUNY ESF

Presentation Type: Poster

Location: UU 111

Presentation #: 71

Timeslot: Session A 9:00-10:00 AM

Abstract: Anthropogenic activity such as industrial smelting and mining results in multiple heavy metals contaminating water and soil. Heavy metal pollutants are toxic to all life, disrupt microbial ecology, and thereby contravene biogeochemical cycling. The microbial response to singular metal toxicity is well studied, however, it has been observed that multiple metal exposures act synergistically to become toxic at concentrations that are lower than single exposures and of environmental relevance. Copper and nickel are heavy metals that are found naturally in the environment and are necessary for life. In excess and in combination, we observe synergistic toxicity inconsistent with the notion that their inhibitory effect is additive in nature. Using Escherichia coli as our model organism due to the extensive resources available, we’ve performed transcriptomics, metabolomics, and a mutant screen of 4000 unique gene deletion mutants to elucidate the mechanism of synergy. Preliminary data suggests that the Fe-S cluster proteins as well as other metalloproteins are being disrupted, with implications of disrupted electron transport. Cysteine and histidine are Fe-S ligands, and their biosynthesis is observed to be upregulated under metal mixture conditions. Experiments are being run as this is written to make sense of the multi-systemic data set, and our findings will be presented in April.