The Combined Toxic Effect of Nickel and Copper on Escherichia coli

Authors: Rebecca Ingrassia, Jennifer Goff, Max Loccisano, Carlos Rodriguez-Bornot, Gray Waldschmidt

SUNY Campus: SUNY ESF

Presentation Type: Poster

Location: UU 111

Presentation #: 66

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

Abstract: It is critical to understand the toxicity of metals on microorganisms due to the various environmental and human health applications of this information. Insight into the effect of metals on microbes would advance antibacterial technologies used for combatting human pathogens in culinary or medical settings and a deeper understanding of the mechanisms and consequences of heavy metal toxicity is important because of how essential microbes are in the fundamental processes that cycle matter. Heavy metals disturb the microbial functions that transform elements and nutrients. In anthropogenically impacted environments, mixed metal contamination is more common than single metal contamination. However, the combined toxicity of multiple metals in microorganisms—including biochemical mechanisms, phenotypic effects and resulting ecological impacts—are largely unknown. This research first explored various binary metal mixture toxicities with the Escherichia coli (E.coli ) K12 strain in search of synergism, where cell growth is inhibited more with exposure to combined metals than with exposure to individual metals. After demonstrating the synergistic toxicity of 30 µM nickel (Ni) mixed with 15 µM copper (Cu), an E. coli single-gene deletion library was screened to unveil notable genes that may be important in the cellular response to this combined metal toxicity. These genes were categorized by their involvement in different biochemical pathways for further exploration. Our preliminary findings suggest that genes involved in the TCA cycle, translation, transcription, metal homeostasis and oxidative stress are